From 34e4cb489a9ff453596af1a8336c822e20da2fa0 Mon Sep 17 00:00:00 2001
From: Goodwitch68 on AcerS7 <56366861+Goodwitch68@users.noreply.github.com>
Date: Sat, 2 Nov 2019 07:34:37 +0100
Subject: [PATCH 01/16] Only transfer, no pull request

---
 helloworld/H15_E1.c | 32 +++++++++++++++++++++++
 helloworld/H15_E2.c |  4 +++
 helloworld/H15_E3.c | 41 +++++++++++++++++++++++++++++
 helloworld/H15_E4.c | 42 +++++++++++++++++++++++++++++
 helloworld/H16_E1.c | 49 ++++++++++++++++++++++++++++++++++
 helloworld/H17_E1.c | 64 +++++++++++++++++++++++++++++++++++++++++++++
 helloworld/H18_E1.c | 39 +++++++++++++++++++++++++++
 7 files changed, 271 insertions(+)
 create mode 100644 helloworld/H15_E1.c
 create mode 100644 helloworld/H15_E2.c
 create mode 100644 helloworld/H15_E3.c
 create mode 100644 helloworld/H15_E4.c
 create mode 100644 helloworld/H16_E1.c
 create mode 100644 helloworld/H17_E1.c
 create mode 100644 helloworld/H18_E1.c

diff --git a/helloworld/H15_E1.c b/helloworld/H15_E1.c
new file mode 100644
index 0000000..2032200
--- /dev/null
+++ b/helloworld/H15_E1.c
@@ -0,0 +1,32 @@
+//1. Rewrite the program in Listing 15.2. This time use the format specifier %c, instead
+//of %s, to print out the character string of the local time on your computer.
+
+#include <stdio.h>
+3: #include <time.h>
+4:
+5: void GetDateTime(void);
+6:
+7: main()
+8: {
+9: printf("Before the GetDateTime() function is called.\n");
+10: GetDateTime();
+11: printf("After the GetDateTime() function is called.\n");
+12: return 0;
+13: }
+14: /* GetDateTime() definition */
+15: void GetDateTime(void)
+16: {
+17: time_t now;
+18:
+19: printf("Within GetDateTime().\n");
+20: time(&now);
+21: printf("Current date and time is: %s\n",
+22: asctime(localtime(&now)));
+23: }
+
+
+
+
+
+
+
diff --git a/helloworld/H15_E2.c b/helloworld/H15_E2.c
new file mode 100644
index 0000000..48fb9b9
--- /dev/null
+++ b/helloworld/H15_E2.c
@@ -0,0 +1,4 @@
+//2. Declare and define a function, called MultiTwo(), that can perform multiplication
+//on two integer variables. Call the MultiTwo() function from the main() function
+//and pass two integers to MultiTwo(). Then print out the result returned by the
+//MultiTwo() function on the screen.
diff --git a/helloworld/H15_E3.c b/helloworld/H15_E3.c
new file mode 100644
index 0000000..11f4345
--- /dev/null
+++ b/helloworld/H15_E3.c
@@ -0,0 +1,41 @@
+//3. Rewrite the program in Listing 15.3. This time, make a function that takes a variable number of int arguments and performs the operation of multiplication on
+//these arguments.
+
+#include <stdio.h>
+#include <stdarg.h>
+
+double AddDouble(int x, ...);
+main () {
+	double d1 = 1.5;
+	double d2 = 2.5;
+	double d3 = 3.5;
+	double d4 = 4.5;
+	
+	printf("Given an argument: %2.1f\n", d1);
+	printf("The result returned by AddDouble() is: %2.1f\n\n",
+	AddDouble(1, d1));
+	printf("Given arguments: %2.1f and %2.1f\n", d1, d2);
+	printf("The result returned by AddDouble() is: %2.1f\n\n",
+	AddDouble(2, d1, d2));
+	printf("Given arguments: %2.1f, %2.1f and %2.1f\n", d1, d2, d3);
+	printf("The result returned by AddDouble() is: %2.1f\n\n",
+	AddDouble(3, d1, d2, d3));
+	printf("Given arguments: %2.1f, %2.1f, %2.1f, and %2.1f\n", d1, d2, d3, d4);
+	printf("The result returned by AddDouble() is: %2.1f\n",
+	AddDouble(4, d1, d2, d3, d4));
+	return 0;
+	}
+	/* definition of AddDouble() */
+	double AddDouble(int x, ...)
+	{
+	va_list arglist;
+	int i;
+	double result = 0.0;
+	
+	printf("The number of arguments is: %d\n", x);
+	va_start (arglist, x);
+	for (i=0; i<x; i++)
+	result += va_arg(arglist, double);
+	va_end (arglist);
+	return result;
+}
\ No newline at end of file
diff --git a/helloworld/H15_E4.c b/helloworld/H15_E4.c
new file mode 100644
index 0000000..3e36b7f
--- /dev/null
+++ b/helloworld/H15_E4.c
@@ -0,0 +1,42 @@
+//4. Rewrite the program in Listing 15.3 again. This time, print out all arguments
+//passed to the AddDouble() function. Does va_arg() fetch each argument in the
+//same order (that is, from left to right) of the argument list passed to AddDouble()?
+
+#include <stdio.h>
+#include <stdarg.h>
+
+double AddDouble(int x, ...);
+main () {
+	double d1 = 1.5;
+	double d2 = 2.5;
+	double d3 = 3.5;
+	double d4 = 4.5;
+	
+	printf("Given an argument: %2.1f\n", d1);
+	printf("The result returned by AddDouble() is: %2.1f\n\n",
+	AddDouble(1, d1));
+	printf("Given arguments: %2.1f and %2.1f\n", d1, d2);
+	printf("The result returned by AddDouble() is: %2.1f\n\n",
+	AddDouble(2, d1, d2));
+	printf("Given arguments: %2.1f, %2.1f and %2.1f\n", d1, d2, d3);
+	printf("The result returned by AddDouble() is: %2.1f\n\n",
+	AddDouble(3, d1, d2, d3));
+	printf("Given arguments: %2.1f, %2.1f, %2.1f, and %2.1f\n", d1, d2, d3, d4);
+	printf("The result returned by AddDouble() is: %2.1f\n",
+	AddDouble(4, d1, d2, d3, d4));
+	return 0;
+	}
+	/* definition of AddDouble() */
+	double AddDouble(int x, ...)
+	{
+	va_list arglist;
+	int i;
+	double result = 0.0;
+	
+	printf("The number of arguments is: %d\n", x);
+	va_start (arglist, x);
+	for (i=0; i<x; i++)
+	result += va_arg(arglist, double);
+	va_end (arglist);
+	return result;
+	}
\ No newline at end of file
diff --git a/helloworld/H16_E1.c b/helloworld/H16_E1.c
new file mode 100644
index 0000000..20753ca
--- /dev/null
+++ b/helloworld/H16_E1.c
@@ -0,0 +1,49 @@
+//1. Given a character string, I like C!, write a program to pass the string to a function that displays the string on the screen.
+
+//2. Rewrite the program in exercise 1. This time, change the string of I like C! to I
+//love C! by moving a pointer that is initialized with the start address of the string
+//and updating the string with new characters. Then, pass the updated string to the
+//function to display the content of the string on the screen.
+
+//3. Given a two-dimensional character array, str, that is initialized as
+//char str[2][15] = { "You know what,", "C is powerful." };
+//write a program to pass the start address of str to a function that prints out the
+//content of the character array.
+
+//4. Rewrite the program in Listing 16.7. This time, the array of pointers is initialized
+//with the following strings:
+//"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", and
+//"Saturday".
+
+#include <stdio.h>
+/* function declarations */
+void StrPrint1(char **str1, int size);
+void StrPrint2(char *str2);
+
+/* main() function */
+main() {
+	char *str[4] = {"There's music in the sighing of a reed;",
+	"There's music in the gushing of a rill;",
+	"There's music in all things if men had ears;",
+	"There earth is but an echo of the spheres.\n"
+	};
+	int i, size = 4;
+	
+	StrPrint1(str, size);
+	for (i=0; i<size; i++)
+	StrPrint2(str[i]);
+	
+	return 0;
+}
+	/* function definition */
+void StrPrint1(char **str1, int size) 24: {
+	int i;
+	/* Print all strings in an array of pointers to strings */
+	for (i=0; i<size; i++)
+		printf("%s\n", str1[i]);
+}
+/* function definition */
+void StrPrint2(char *str2) 32: {
+/* Prints one string at a time */
+	printf("%s\n", str2);
+}
\ No newline at end of file
diff --git a/helloworld/H17_E1.c b/helloworld/H17_E1.c
new file mode 100644
index 0000000..a85d13d
--- /dev/null
+++ b/helloworld/H17_E1.c
@@ -0,0 +1,64 @@
+//1. Write a program to ask the user to enter the total number of bytes he or she wants
+//to allocate. Then, initialize the allocated memory with consecutive integers, starting
+//from 1. Add all the integers contained by the memory block and print out the final
+//result on the screen.
+//2. Write a program that allocates a block of memory space to hold 100 items of the
+//float data type by calling the calloc() function. Then, reallocate the block of
+//memory in order to hold 50 more items of the float data type.
+//3. Write a program to ask the user to enter the total number of float data. Then use
+//the calloc() and malloc() functions to allocate two memory blocks with the
+//same size specified by the number, and print out the initial values of the two memory blocks.
+//4. Rewrite the program in Listing 17.4. This time, use the two special cases of the
+//realloc() function to replace the malloc() and free() functions.
+
+ /* 17L04.c: Using the realloc() function */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+/* function declaration */
+void StrCopy(char *str1, char *str2);
+/* main() function */
+main() {
+	char *str[4] = {"There's music in the sighing of a reed;",
+	"There's music in the gushing of a rill;",
+	"There's music in all things if men had ears;",
+	"There earth is but an echo of the spheres.\n"
+	};
+	char *ptr;
+	int i;
+	
+	int termination = 0;
+	
+	ptr = malloc((strlen(str[0]) + 1) * sizeof(char));
+	if (ptr == NULL){
+	printf("malloc() failed.\n");
+	termination = 1;
+	}
+	else{
+	StrCopy(str[0], ptr);
+	printf("%s\n", ptr);
+	for (i=1; i<4; i++){
+	ptr = realloc(ptr, (strlen(str[i]) + 1) * sizeof(char));
+	if (ptr == NULL){
+	printf("realloc() failed.\n");
+	termination = 1;
+	i = 4; /* break the fro loop */
+	}
+	else{
+	StrCopy(str[i], ptr);
+	printf("%s\n", ptr);
+	}
+	}
+	}
+	free(ptr);
+	return termination;
+	}
+	/* funciton definition */
+	void StrCopy(char *str1, char *str2)
+	{
+	int i;
+	
+	for (i=0; str1[i]; i++)
+	str2[i] = str1[i];
+	str2[i] = ‘\0';
+	}
\ No newline at end of file
diff --git a/helloworld/H18_E1.c b/helloworld/H18_E1.c
new file mode 100644
index 0000000..a1a6d96
--- /dev/null
+++ b/helloworld/H18_E1.c
@@ -0,0 +1,39 @@
+//1. Write a program to print out the values represented by the enumerated names
+//declared in Quiz question 2 in this hour.
+//2. Given the following declarations:
+//typedef char WORD;
+//typedef int SHORT;
+//typedef long LONG;
+//typedef float FLOAT;
+//typedef double DFLOAT;
+//write a program to measure the sizes of the synonyms to the data types.
+//3. Rewrite the program in Listing 18.4. This time, add integers starting at the value of
+//MIN_NUM instead of the value of MAX_NUM.
+
+#include <stdio.h>
+enum con{MIN_NUM = 0,
+MAX_NUM = 100};
+int fRecur(int n);
+
+main() {
+	int i, sum1, sum2;
+	
+	sum1 = sum2 = 0;
+	for (i=1; i<=MAX_NUM; i++)
+		sum1 += i;
+		printf("The value of sum1 is %d.\n", sum1);
+	sum2 = fRecur(MAX_NUM);
+	printf("The value returned by fRecur() is %d.\n", sum2);
+	
+	return 0;
+}
+/* function definition */
+int fRecur(int n) {
+	if (n == MIN_NUM)
+	return 0;
+	return fRecur(n - 1) + n;
+}
+
+//4. Write a program that accepts command-line arguments. If the number of command-line arguments, not including the name of the executable itself, is less than
+//two, print out the usage format of the program and ask the user to reenter the command-line arguments. Otherwise, display all command-line arguments entered by
+//the user.

From bdcf78095d0a6cf4f1dd71ac79caf0f6f95e5a9b Mon Sep 17 00:00:00 2001
From: Goodwitch68 on AcerS7 <56366861+Goodwitch68@users.noreply.github.com>
Date: Mon, 4 Nov 2019 12:07:22 +0100
Subject: [PATCH 02/16] H15_E1-2 are ready for check

---
 helloworld/H15_E1.c | 42 +++++++++++++++++++++---------------------
 helloworld/H15_E2.c | 16 ++++++++++++++++
 2 files changed, 37 insertions(+), 21 deletions(-)

diff --git a/helloworld/H15_E1.c b/helloworld/H15_E1.c
index 2032200..ff15b87 100644
--- a/helloworld/H15_E1.c
+++ b/helloworld/H15_E1.c
@@ -2,27 +2,27 @@
 //of %s, to print out the character string of the local time on your computer.
 
 #include <stdio.h>
-3: #include <time.h>
-4:
-5: void GetDateTime(void);
-6:
-7: main()
-8: {
-9: printf("Before the GetDateTime() function is called.\n");
-10: GetDateTime();
-11: printf("After the GetDateTime() function is called.\n");
-12: return 0;
-13: }
-14: /* GetDateTime() definition */
-15: void GetDateTime(void)
-16: {
-17: time_t now;
-18:
-19: printf("Within GetDateTime().\n");
-20: time(&now);
-21: printf("Current date and time is: %s\n",
-22: asctime(localtime(&now)));
-23: }
+#include <time.h>
+
+void GetDateTime(void);
+
+main() {
+	printf("Before the GetDateTime() function is called.\n");
+	GetDateTime();
+	printf("After the GetDateTime() function is called.\n");
+	return 0;
+}
+/* GetDateTime() definition */
+void GetDateTime(void) {
+	time_t now;
+	int i;
+	char *str;
+	printf("Within GetDateTime().\n");
+	time(&now);
+	str = asctime (localtime (&now));
+	printf("Current date and time is: ");
+	for (i=0; str[i]; i++) printf("%c", str[i]);
+}
 
 
 
diff --git a/helloworld/H15_E2.c b/helloworld/H15_E2.c
index 48fb9b9..9a3a225 100644
--- a/helloworld/H15_E2.c
+++ b/helloworld/H15_E2.c
@@ -2,3 +2,19 @@
 //on two integer variables. Call the MultiTwo() function from the main() function
 //and pass two integers to MultiTwo(). Then print out the result returned by the
 //MultiTwo() function on the screen.
+
+#include <stdio.h>
+
+MultiTwo(int x, int y);
+
+main () {
+	 int i = 24;
+	 int j = 13;
+	 printf("%d multiplied by %d equal %d.\n", i, j, MultiTwo(i,j));
+	 return 0;
+}
+
+MultiTwo(int x, int y) {
+	return x * y;
+}
+

From 006e8e3bf802c382e2b0b3d38d4470064635cc59 Mon Sep 17 00:00:00 2001
From: Goodwitch68 on AcerS7 <56366861+Goodwitch68@users.noreply.github.com>
Date: Mon, 4 Nov 2019 12:08:23 +0100
Subject: [PATCH 03/16] H14_E3 and 4 have problem with solving, pls help

---
 helloworld/H15_E3.c | 31 ++++++++++++++-----------------
 helloworld/H15_E4.c | 28 ++++++++++++----------------
 2 files changed, 26 insertions(+), 33 deletions(-)

diff --git a/helloworld/H15_E3.c b/helloworld/H15_E3.c
index 11f4345..42b52d8 100644
--- a/helloworld/H15_E3.c
+++ b/helloworld/H15_E3.c
@@ -1,4 +1,5 @@
-//3. Rewrite the program in Listing 15.3. This time, make a function that takes a variable number of int arguments and performs the operation of multiplication on
+//3. Rewrite the program in Listing 15.3. This time, make a function that takes 
+//a variable number of int arguments and performs the operation of multiplication on
 //these arguments.
 
 #include <stdio.h>
@@ -12,30 +13,26 @@ main () {
 	double d4 = 4.5;
 	
 	printf("Given an argument: %2.1f\n", d1);
-	printf("The result returned by AddDouble() is: %2.1f\n\n",
-	AddDouble(1, d1));
+	printf("The result returned by AddDouble() is: %2.1f\n\n", 	AddDouble(1, d1));
 	printf("Given arguments: %2.1f and %2.1f\n", d1, d2);
-	printf("The result returned by AddDouble() is: %2.1f\n\n",
-	AddDouble(2, d1, d2));
+	printf("The result returned by AddDouble() is: %2.1f\n\n", 	AddDouble(2, d1, d2));
 	printf("Given arguments: %2.1f, %2.1f and %2.1f\n", d1, d2, d3);
-	printf("The result returned by AddDouble() is: %2.1f\n\n",
-	AddDouble(3, d1, d2, d3));
+	printf("The result returned by AddDouble() is: %2.1f\n\n", 	AddDouble(3, d1, d2, d3));
 	printf("Given arguments: %2.1f, %2.1f, %2.1f, and %2.1f\n", d1, d2, d3, d4);
-	printf("The result returned by AddDouble() is: %2.1f\n",
-	AddDouble(4, d1, d2, d3, d4));
+	printf("The result returned by AddDouble() is: %2.1f\n", AddDouble(4, d1, d2, d3, d4));
 	return 0;
-	}
+}
 	/* definition of AddDouble() */
-	double AddDouble(int x, ...)
-	{
+double AddDouble(int x, ...) {
 	va_list arglist;
 	int i;
 	double result = 0.0;
-	
 	printf("The number of arguments is: %d\n", x);
 	va_start (arglist, x);
-	for (i=0; i<x; i++)
-	result += va_arg(arglist, double);
+	for (i=0; i<x; i++) result += va_arg(arglist, double);
 	va_end (arglist);
-	return result;
-}
\ No newline at end of file
+return result;
+}
+
+
+//elakadtam, mert ne értem a változó argumentumu függvényeket :-(
diff --git a/helloworld/H15_E4.c b/helloworld/H15_E4.c
index 3e36b7f..a7440e7 100644
--- a/helloworld/H15_E4.c
+++ b/helloworld/H15_E4.c
@@ -13,30 +13,26 @@ main () {
 	double d4 = 4.5;
 	
 	printf("Given an argument: %2.1f\n", d1);
-	printf("The result returned by AddDouble() is: %2.1f\n\n",
-	AddDouble(1, d1));
+	printf("The result returned by AddDouble() is: %2.1f\n\n", 	AddDouble(1, d1));
 	printf("Given arguments: %2.1f and %2.1f\n", d1, d2);
-	printf("The result returned by AddDouble() is: %2.1f\n\n",
-	AddDouble(2, d1, d2));
+	printf("The result returned by AddDouble() is: %2.1f\n\n", 	AddDouble(2, d1, d2));
 	printf("Given arguments: %2.1f, %2.1f and %2.1f\n", d1, d2, d3);
-	printf("The result returned by AddDouble() is: %2.1f\n\n",
-	AddDouble(3, d1, d2, d3));
+	printf("The result returned by AddDouble() is: %2.1f\n\n", 	AddDouble(3, d1, d2, d3));
 	printf("Given arguments: %2.1f, %2.1f, %2.1f, and %2.1f\n", d1, d2, d3, d4);
-	printf("The result returned by AddDouble() is: %2.1f\n",
-	AddDouble(4, d1, d2, d3, d4));
+	printf("The result returned by AddDouble() is: %2.1f\n", AddDouble(4, d1, d2, d3, d4));
 	return 0;
-	}
+}
 	/* definition of AddDouble() */
-	double AddDouble(int x, ...)
-	{
+double AddDouble(int x, ...) {
 	va_list arglist;
 	int i;
 	double result = 0.0;
-	
 	printf("The number of arguments is: %d\n", x);
 	va_start (arglist, x);
-	for (i=0; i<x; i++)
-	result += va_arg(arglist, double);
+	for (i=0; i<x; i++) result += va_arg(arglist, double);
 	va_end (arglist);
-	return result;
-	}
\ No newline at end of file
+return result;
+}
+	
+	//na ezzel ugyanaz a problémám, mint az előző feladattal. :-(
+	
\ No newline at end of file

From d3130692fc1fc79edddefadfe925999bae1d06eb Mon Sep 17 00:00:00 2001
From: Goodwitch68 on AcerS7 <56366861+Goodwitch68@users.noreply.github.com>
Date: Mon, 4 Nov 2019 14:54:06 +0100
Subject: [PATCH 04/16] H16 ready for checking

---
 helloworld/H16_E1.c | 56 ++++++++++++---------------------------------
 helloworld/H16_E2.c | 25 ++++++++++++++++++++
 helloworld/H16_E3.c | 25 ++++++++++++++++++++
 helloworld/H16_E4.c | 35 ++++++++++++++++++++++++++++
 4 files changed, 99 insertions(+), 42 deletions(-)
 create mode 100644 helloworld/H16_E2.c
 create mode 100644 helloworld/H16_E3.c
 create mode 100644 helloworld/H16_E4.c

diff --git a/helloworld/H16_E1.c b/helloworld/H16_E1.c
index 20753ca..b5bd7bb 100644
--- a/helloworld/H16_E1.c
+++ b/helloworld/H16_E1.c
@@ -1,49 +1,21 @@
-//1. Given a character string, I like C!, write a program to pass the string to a function that displays the string on the screen.
-
-//2. Rewrite the program in exercise 1. This time, change the string of I like C! to I
-//love C! by moving a pointer that is initialized with the start address of the string
-//and updating the string with new characters. Then, pass the updated string to the
-//function to display the content of the string on the screen.
-
-//3. Given a two-dimensional character array, str, that is initialized as
-//char str[2][15] = { "You know what,", "C is powerful." };
-//write a program to pass the start address of str to a function that prints out the
-//content of the character array.
-
-//4. Rewrite the program in Listing 16.7. This time, the array of pointers is initialized
-//with the following strings:
-//"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", and
-//"Saturday".
+//1. Given a character string, I like C!, write a program to pass the string to 
+//a function that displays the string on the screen.
 
 #include <stdio.h>
-/* function declarations */
-void StrPrint1(char **str1, int size);
-void StrPrint2(char *str2);
 
-/* main() function */
+void Strprint(char *ch);
+
 main() {
-	char *str[4] = {"There's music in the sighing of a reed;",
-	"There's music in the gushing of a rill;",
-	"There's music in all things if men had ears;",
-	"There earth is but an echo of the spheres.\n"
-	};
-	int i, size = 4;
-	
-	StrPrint1(str, size);
-	for (i=0; i<size; i++)
-	StrPrint2(str[i]);
-	
+	char str[] = "I like C!";
+	char *ptr_str;
+	ptr_str = str;
+	Strprint(ptr_str);
 	return 0;
 }
-	/* function definition */
-void StrPrint1(char **str1, int size) 24: {
-	int i;
-	/* Print all strings in an array of pointers to strings */
-	for (i=0; i<size; i++)
-		printf("%s\n", str1[i]);
+
+//function defaul
+
+void Strprint(char *ch) {
+	printf("%s\n", ch);
 }
-/* function definition */
-void StrPrint2(char *str2) 32: {
-/* Prints one string at a time */
-	printf("%s\n", str2);
-}
\ No newline at end of file
+
diff --git a/helloworld/H16_E2.c b/helloworld/H16_E2.c
new file mode 100644
index 0000000..712176e
--- /dev/null
+++ b/helloworld/H16_E2.c
@@ -0,0 +1,25 @@
+//2. Rewrite the program in exercise 1. This time, change the string of I like C! to I
+//love C! by moving a pointer that is initialized with the start address of the string
+//and updating the string with new characters. Then, pass the updated string to the
+//function to display the content of the string on the screen.#include <stdio.h>
+#include <stdio.h>
+void Strprint(char *ch);
+
+main() {
+	char str[] = "I like C!";
+	char *ptr_str;
+	ptr_str = str;
+	*(ptr_str + 3) = 'o';
+	*(ptr_str + 4) = 'v';
+	Strprint(ptr_str);
+	return 0;
+}
+
+//function definition
+
+void Strprint(char *ch) {
+	printf("%s\n", ch);
+}
+
+
+
diff --git a/helloworld/H16_E3.c b/helloworld/H16_E3.c
new file mode 100644
index 0000000..73d66b5
--- /dev/null
+++ b/helloworld/H16_E3.c
@@ -0,0 +1,25 @@
+//3. Given a two-dimensional character array, str, that is initialized as
+//char str[2][15] = { "You know what,", "C is powerful." };
+//write a program to pass the start address of str to a function that prints out the
+//content of the character array.
+
+#include <stdio.h>
+
+void Strprint(char * ch [][15]);
+
+main() {
+	char str[2][15] = { "You know what,", "C is powerful." };
+	char *ptr_str;
+	ptr_str = str;
+	Strprint(ptr_str);
+	Strprint(ptr_str + 15);
+	return 0;
+}
+
+//function defaul
+
+void Strprint(char *ch [][15]) {
+	printf("%s\n", ch);
+}
+
+//fordításkor nyom egy csomó warningot, amit nem tudok értelmezni, viszont működik.
\ No newline at end of file
diff --git a/helloworld/H16_E4.c b/helloworld/H16_E4.c
new file mode 100644
index 0000000..b7ead34
--- /dev/null
+++ b/helloworld/H16_E4.c
@@ -0,0 +1,35 @@
+//4. Rewrite the program in Listing 16.7. This time, the array of pointers is initialized
+//with the following strings:
+//"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", and
+//"Saturday".
+
+#include <stdio.h>
+/* function declarations */
+void StrPrint1(char **str1, int size);
+void StrPrint2(char *str2);
+
+/* main() function */
+main() {
+	char *str[7] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", 
+"Saturday\n"};
+	int i, size = 7;
+	StrPrint1(str, size);
+	for (i=0; i<size; i++)
+	StrPrint2(str[i]);
+	
+	return 0;
+}
+	/* function definition */
+void StrPrint1(char **str1, int size) {
+	int i;
+	/* Print all strings in an array of pointers to strings */
+	for (i=0; i<size; i++)
+		printf("%s\n", str1[i]);
+}
+/* function definition */
+void StrPrint2(char *str2) {
+/* Prints one string at a time */
+	printf("%s\n", str2);
+}
+
+

From 90f068dca0dd2452f5608c5f73aa4b4da3024cd5 Mon Sep 17 00:00:00 2001
From: Goodwitch68 on AcerS7 <56366861+Goodwitch68@users.noreply.github.com>
Date: Tue, 5 Nov 2019 13:27:50 +0100
Subject: [PATCH 05/16] H17_E1 ready for checking

---
 helloworld/H17_E1.c | 85 ++++++++++++++++++---------------------------
 1 file changed, 33 insertions(+), 52 deletions(-)

diff --git a/helloworld/H17_E1.c b/helloworld/H17_E1.c
index a85d13d..111aec1 100644
--- a/helloworld/H17_E1.c
+++ b/helloworld/H17_E1.c
@@ -2,63 +2,44 @@
 //to allocate. Then, initialize the allocated memory with consecutive integers, starting
 //from 1. Add all the integers contained by the memory block and print out the final
 //result on the screen.
-//2. Write a program that allocates a block of memory space to hold 100 items of the
-//float data type by calling the calloc() function. Then, reallocate the block of
-//memory in order to hold 50 more items of the float data type.
-//3. Write a program to ask the user to enter the total number of float data. Then use
-//the calloc() and malloc() functions to allocate two memory blocks with the
-//same size specified by the number, and print out the initial values of the two memory blocks.
-//4. Rewrite the program in Listing 17.4. This time, use the two special cases of the
-//realloc() function to replace the malloc() and free() functions.
 
- /* 17L04.c: Using the realloc() function */
 #include <stdio.h>
 #include <stdlib.h>
-#include <string.h>
+
 /* function declaration */
-void StrCopy(char *str1, char *str2);
+int SumNumbers (int x);
+
 /* main() function */
+
 main() {
-	char *str[4] = {"There's music in the sighing of a reed;",
-	"There's music in the gushing of a rill;",
-	"There's music in all things if men had ears;",
-	"There earth is but an echo of the spheres.\n"
-	};
-	char *ptr;
-	int i;
-	
-	int termination = 0;
-	
-	ptr = malloc((strlen(str[0]) + 1) * sizeof(char));
-	if (ptr == NULL){
-	printf("malloc() failed.\n");
-	termination = 1;
-	}
-	else{
-	StrCopy(str[0], ptr);
-	printf("%s\n", ptr);
-	for (i=1; i<4; i++){
-	ptr = realloc(ptr, (strlen(str[i]) + 1) * sizeof(char));
-	if (ptr == NULL){
-	printf("realloc() failed.\n");
-	termination = 1;
-	i = 4; /* break the fro loop */
-	}
-	else{
-	StrCopy(str[i], ptr);
-	printf("%s\n", ptr);
+	int SizeofAllmemory;
+	int *ptr_x;
+	int sum = 0;
+	int result;
+	setbuf(stdout, NULL);
+	printf("Enter the total number of bytes you want to allocate:");
+	scanf("%d", &SizeofAllmemory);
+	ptr_x = malloc (SizeofAllmemory/2 * sizeof(int));
+	//ptr_x = malloc (SizeofAllmemory); Ez vajon miért nem jó helyette? segmentation faultot ad vissza
+	if (ptr_x != NULL){
+		for (int i = 0; i < SizeofAllmemory/2; i++){
+			ptr_x[i] = i + 1;
+			printf("%d\n", *(ptr_x + i));
+		}
+		printf("Az összeg az elején: %d\n", sum);
+		for (int i = 0; i < SizeofAllmemory/2; i++){
+			sum += ptr_x[i];
+			printf("Az összeg most: %d\n", sum);
+		}
+		printf("The sum is %d\n", sum);
+		result = 0;
 	}
+	else {
+		printf("malloc() function failed.\n");
+		result = 1;
 	}
-	}
-	free(ptr);
-	return termination;
-	}
-	/* funciton definition */
-	void StrCopy(char *str1, char *str2)
-	{
-	int i;
-	
-	for (i=0; str1[i]; i++)
-	str2[i] = str1[i];
-	str2[i] = ‘\0';
-	}
\ No newline at end of file
+	printf("%d", result);
+	return result;
+}
+
+

From 3d4c18a424bd0415ea55d1a480b7b1b12ea32737 Mon Sep 17 00:00:00 2001
From: Goodwitch68 on AcerS7 <56366861+Goodwitch68@users.noreply.github.com>
Date: Tue, 5 Nov 2019 13:31:19 +0100
Subject: [PATCH 06/16] H17_E1 this is ready for checking

---
 helloworld/H17_E1.c | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/helloworld/H17_E1.c b/helloworld/H17_E1.c
index 111aec1..07da852 100644
--- a/helloworld/H17_E1.c
+++ b/helloworld/H17_E1.c
@@ -6,11 +6,6 @@
 #include <stdio.h>
 #include <stdlib.h>
 
-/* function declaration */
-int SumNumbers (int x);
-
-/* main() function */
-
 main() {
 	int SizeofAllmemory;
 	int *ptr_x;

From 0ad54d3a7da8ff1dff2573cf63e9a6cfe26c8039 Mon Sep 17 00:00:00 2001
From: Goodwitch68 on AcerS7 <56366861+Goodwitch68@users.noreply.github.com>
Date: Tue, 5 Nov 2019 13:45:29 +0100
Subject: [PATCH 07/16] H17_E2 ready for checking

---
 helloworld/H17_E2.c | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)
 create mode 100644 helloworld/H17_E2.c

diff --git a/helloworld/H17_E2.c b/helloworld/H17_E2.c
new file mode 100644
index 0000000..51dcae9
--- /dev/null
+++ b/helloworld/H17_E2.c
@@ -0,0 +1,31 @@
+//2. Write a program that allocates a block of memory space to hold 100 items of the
+//float data type by calling the calloc() function. Then, reallocate the block of
+//memory in order to hold 50 more items of the float data type.
+
+
+#include <stdio.h>
+#include <stdlib.h>
+
+main() {
+	float *ptr_x;
+	int result;
+	ptr_x = calloc (100, sizeof(float));
+	if (ptr_x != NULL){
+		result = 0;
+		printf("First allocation is done\n");
+	}
+	else {
+		printf("The first allocation wasn't successful! \n");
+		result = 1;
+	}
+	ptr_x = realloc (ptr_x, 150);
+	if (ptr_x != NULL){
+		result = 0;
+		printf("The reallocation is done\n");
+	}
+	else {
+		printf("The reallocation wasn't successful! \n");
+		result = 1;
+	}
+	return result;
+}
\ No newline at end of file

From df4851220a54a5d4a5a03531a75ad4b8e027904d Mon Sep 17 00:00:00 2001
From: Goodwitch68 on AcerS7 <56366861+Goodwitch68@users.noreply.github.com>
Date: Tue, 5 Nov 2019 13:59:25 +0100
Subject: [PATCH 08/16] H17_3 ready for checking

---
 helloworld/H17_E3.c | 36 ++++++++++++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)
 create mode 100644 helloworld/H17_E3.c

diff --git a/helloworld/H17_E3.c b/helloworld/H17_E3.c
new file mode 100644
index 0000000..2e836a3
--- /dev/null
+++ b/helloworld/H17_E3.c
@@ -0,0 +1,36 @@
+
+//3. Write a program to ask the user to enter the total number of float data. Then use
+//the calloc() and malloc() functions to allocate two memory blocks with the
+//same size specified by the number, and print out the initial values of the two memory blocks.
+
+#include <stdio.h>
+#include <stdlib.h>
+
+main() {
+	int Nodata;
+	float *ptr_x1;
+	float *ptr_x2;
+	int result;
+	setbuf(stdout, NULL);
+	printf("Enter the total number of float data you want to allocate:");
+	scanf("%d", &Nodata);
+	ptr_x1 = malloc (Nodata * sizeof(float));
+	if (ptr_x1 != NULL){
+		result = 0;
+		printf("First allocation is done\n, the first value of the block is: %f\n", *ptr_x1);
+	}
+	else {
+		printf("The first allocation wasn't successful! \n");
+		result = 1;
+	}
+	ptr_x2 = calloc (Nodata, sizeof(float));
+	if (ptr_x2 != NULL){
+		result = 0;
+		printf("Second allocation is done\n, the first value of the block is: %f\n", *ptr_x2);
+	}
+	else {
+		printf("The 2nd allocation wasn't successful! \n");
+		result = 1;
+	}
+	return result;
+}
\ No newline at end of file

From 41903885c93a776c3263581907678aaff103240e Mon Sep 17 00:00:00 2001
From: Goodwitch68 on AcerS7 <56366861+Goodwitch68@users.noreply.github.com>
Date: Tue, 5 Nov 2019 14:11:03 +0100
Subject: [PATCH 09/16] H14_E4 ready for checking

---
 helloworld/H17_E4.c | 54 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 54 insertions(+)
 create mode 100644 helloworld/H17_E4.c

diff --git a/helloworld/H17_E4.c b/helloworld/H17_E4.c
new file mode 100644
index 0000000..ca5531b
--- /dev/null
+++ b/helloworld/H17_E4.c
@@ -0,0 +1,54 @@
+//4. Rewrite the program in Listing 17.4. This time, use the two special cases of the
+//realloc() function to replace the malloc() and free() functions.
+
+ /* 17L04.c: Using the realloc() function */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+/* function declaration */
+void StrCopy(char *str1, char *str2);
+/* main() function */
+main() {
+	char *str[4] = {"There's music in the sighing of a reed;",
+	"There's music in the gushing of a rill;",
+	"There's music in all things if men had ears;",
+	"There earth is but an echo of the spheres.\n"
+	};
+	char *ptr;
+	int i;
+	
+	int termination = 0;
+	
+	ptr = realloc(NULL, (strlen(str[0]) + 1) * sizeof(char)); //ptr = malloc((strlen(str[0]) + 1) * sizeof(char));
+	if (ptr == NULL){
+	printf("malloc() failed.\n");
+	termination = 1;
+	}
+	else{
+	StrCopy(str[0], ptr);
+	printf("%s\n", ptr);
+	for (i=1; i<4; i++){
+	ptr = realloc(ptr, (strlen(str[i]) + 1) * sizeof(char));
+	if (ptr == NULL){
+	printf("realloc() failed.\n");
+	termination = 1;
+	i = 4; /* break the fro loop */
+	}
+	else{
+	StrCopy(str[i], ptr);
+	printf("%s\n", ptr);
+	}
+	}
+	}
+	realloc(ptr, 0); //free(ptr)
+	return termination;
+	}
+	/* funciton definition */
+	void StrCopy(char *str1, char *str2)
+	{
+	int i;
+	
+	for (i=0; str1[i]; i++)
+	str2[i] = str1[i];
+	str2[i] = '\0';
+	}
\ No newline at end of file

From 0a95a6d32f7b8c189a08b1fb785c8e8df58288f5 Mon Sep 17 00:00:00 2001
From: Goodwitch68 on AcerS7 <56366861+Goodwitch68@users.noreply.github.com>
Date: Wed, 6 Nov 2019 10:04:03 +0100
Subject: [PATCH 10/16] H18_E1 ready for checking

---
 helloworld/H18_E1.c | 41 ++++++++---------------------------------
 1 file changed, 8 insertions(+), 33 deletions(-)

diff --git a/helloworld/H18_E1.c b/helloworld/H18_E1.c
index a1a6d96..33f2b53 100644
--- a/helloworld/H18_E1.c
+++ b/helloworld/H18_E1.c
@@ -1,39 +1,14 @@
 //1. Write a program to print out the values represented by the enumerated names
 //declared in Quiz question 2 in this hour.
-//2. Given the following declarations:
-//typedef char WORD;
-//typedef int SHORT;
-//typedef long LONG;
-//typedef float FLOAT;
-//typedef double DFLOAT;
-//write a program to measure the sizes of the synonyms to the data types.
-//3. Rewrite the program in Listing 18.4. This time, add integers starting at the value of
-//MIN_NUM instead of the value of MAX_NUM.
+//enum tag { name1,name2 = 10,name3,name4 };
 
 #include <stdio.h>
-enum con{MIN_NUM = 0,
-MAX_NUM = 100};
-int fRecur(int n);
-
 main() {
-	int i, sum1, sum2;
-	
-	sum1 = sum2 = 0;
-	for (i=1; i<=MAX_NUM; i++)
-		sum1 += i;
-		printf("The value of sum1 is %d.\n", sum1);
-	sum2 = fRecur(MAX_NUM);
-	printf("The value returned by fRecur() is %d.\n", sum2);
-	
-	return 0;
-}
-/* function definition */
-int fRecur(int n) {
-	if (n == MIN_NUM)
-	return 0;
-	return fRecur(n - 1) + n;
-}
+enum tag { name1, name2 = 10,name3,name4 };
+printf("The value represented by name1 is: %d\n", name1);
+printf("The value represented by name2 is: %d\n", name2);
+printf("The value represented by name3 is: %d\n", name3);
+printf("The value represented by name4 is: %d\n", name4); 
 
-//4. Write a program that accepts command-line arguments. If the number of command-line arguments, not including the name of the executable itself, is less than
-//two, print out the usage format of the program and ask the user to reenter the command-line arguments. Otherwise, display all command-line arguments entered by
-//the user.
+return 0;
+}

From a31b58166b539cbe061c0b5c59e1f78ed4907514 Mon Sep 17 00:00:00 2001
From: Goodwitch68 on AcerS7 <56366861+Goodwitch68@users.noreply.github.com>
Date: Wed, 6 Nov 2019 10:08:40 +0100
Subject: [PATCH 11/16] H18_E2 ready for checking

---
 helloworld/H18_E2.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 helloworld/H18_E2.c

diff --git a/helloworld/H18_E2.c b/helloworld/H18_E2.c
new file mode 100644
index 0000000..b200b7a
--- /dev/null
+++ b/helloworld/H18_E2.c
@@ -0,0 +1,25 @@
+//2. Given the following declarations:
+//typedef char WORD;
+//typedef int SHORT;
+//typedef long LONG;
+//typedef float FLOAT;
+//typedef double DFLOAT;
+//write a program to measure the sizes of the synonyms to the data types.
+
+#include <stdio.h>
+main() {
+typedef char WORD;
+typedef int SHORT;
+typedef long LONG;
+typedef float FLOAT;
+typedef double DFLOAT;
+
+printf("The size of WORD is: %d\n", sizeof(WORD));
+printf("The size of SHORT is: %d\n", sizeof(SHORT));
+printf("The size of LONG is: %d\n", sizeof(LONG)); 
+printf("The size of FLOAT is: %d\n", sizeof(FLOAT));
+printf("The size of DFLOAT is: %d\n", sizeof(DFLOAT));
+
+return 0;
+}
+

From 0b76c8f94318c223b99f92360bc549ece97f48dc Mon Sep 17 00:00:00 2001
From: Goodwitch68 on AcerS7 <56366861+Goodwitch68@users.noreply.github.com>
Date: Wed, 6 Nov 2019 10:12:52 +0100
Subject: [PATCH 12/16] H18_E3 ready for checking

---
 helloworld/H18_E3.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)
 create mode 100644 helloworld/H18_E3.c

diff --git a/helloworld/H18_E3.c b/helloworld/H18_E3.c
new file mode 100644
index 0000000..f15cce8
--- /dev/null
+++ b/helloworld/H18_E3.c
@@ -0,0 +1,27 @@
+//3. Rewrite the program in Listing 18.4. This time, add integers starting at the value of
+//MIN_NUM instead of the value of MAX_NUM.
+
+#include <stdio.h>
+enum con{MIN_NUM = 0,
+MAX_NUM = 100};
+int fRecur(int n);
+
+main() {
+	int i, sum1, sum2;
+	
+	sum1 = sum2 = 0;
+	for (i=1; i<=MAX_NUM; i++)
+		sum1 += i;
+		printf("The value of sum1 is %d.\n", sum1);
+	sum2 = fRecur(MIN_NUM);
+	printf("The value returned by fRecur() is %d.\n", sum2);
+	
+	return 0;
+}
+/* function definition */
+int fRecur(int n) {
+	if (n > MAX_NUM)
+	return 0;
+	return fRecur(n + 1) + n;
+}
+

From d02f23d014de57633c9954c955116d168fe5843d Mon Sep 17 00:00:00 2001
From: Goodwitch68 on AcerS7 <56366861+Goodwitch68@users.noreply.github.com>
Date: Wed, 6 Nov 2019 10:26:47 +0100
Subject: [PATCH 13/16] H18_E4 ready for checking

---
 helloworld/H18_E4.c | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 helloworld/H18_E4.c

diff --git a/helloworld/H18_E4.c b/helloworld/H18_E4.c
new file mode 100644
index 0000000..e8d7cab
--- /dev/null
+++ b/helloworld/H18_E4.c
@@ -0,0 +1,25 @@
+//4. Write a program that accepts command-line arguments. If the number of 
+//command-line arguments, not including the name of the executable itself, 
+//is less than two, print out the usage format of the program and 
+//ask the user to reenter the command-line arguments.
+//Otherwise, display all command-line arguments entered by
+//the user.
+
+#include <stdio.h>
+main (int argc, char *argv[]) {
+	int i;
+	if (argc < 2) {
+		printf("The usage of this program is:\n");
+		printf("a.EXE argument1 argument2 [...argumentN]\n");
+		printf("Please start the program again'");
+	}
+	else {
+		printf("The number of the command-line arguments are: %d\n", argc);
+		printf("The command-line arguments are:\n");
+		for (i=1; i<argc; i++){
+			printf("%s ", argv[i]);
+		}
+		printf("\n");
+	}
+	return 0;
+}
\ No newline at end of file

From 485b2290894a7c58cf5ec7471094a0ee017064ba Mon Sep 17 00:00:00 2001
From: Goodwitch68 on AcerS7 <56366861+Goodwitch68@users.noreply.github.com>
Date: Sat, 9 Nov 2019 08:12:53 +0100
Subject: [PATCH 14/16] Have problem with H15_E3 -E4, I can't understand the
 functions with variable number of arguments. Please help

---
 helloworld/H15_E3.c | 8 ++++----
 helloworld/H15_E4.c | 4 ++--
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/helloworld/H15_E3.c b/helloworld/H15_E3.c
index 42b52d8..286a822 100644
--- a/helloworld/H15_E3.c
+++ b/helloworld/H15_E3.c
@@ -13,11 +13,11 @@ main () {
 	double d4 = 4.5;
 	
 	printf("Given an argument: %2.1f\n", d1);
-	printf("The result returned by AddDouble() is: %2.1f\n\n", 	AddDouble(1, d1));
+	printf("The result returned by AddDouble() is: %2.1f\n\n", AddDouble(1, d1));
 	printf("Given arguments: %2.1f and %2.1f\n", d1, d2);
-	printf("The result returned by AddDouble() is: %2.1f\n\n", 	AddDouble(2, d1, d2));
+	printf("The result returned by AddDouble() is: %2.1f\n\n", AddDouble(2, d1, d2));
 	printf("Given arguments: %2.1f, %2.1f and %2.1f\n", d1, d2, d3);
-	printf("The result returned by AddDouble() is: %2.1f\n\n", 	AddDouble(3, d1, d2, d3));
+	printf("The result returned by AddDouble() is: %2.1f\n\n", AddDouble(3, d1, d2, d3));
 	printf("Given arguments: %2.1f, %2.1f, %2.1f, and %2.1f\n", d1, d2, d3, d4);
 	printf("The result returned by AddDouble() is: %2.1f\n", AddDouble(4, d1, d2, d3, d4));
 	return 0;
@@ -32,7 +32,7 @@ double AddDouble(int x, ...) {
 	for (i=0; i<x; i++) result += va_arg(arglist, double);
 	va_end (arglist);
 return result;
+//elakadtam, mert nem értem a változó argumentumu függvényeket :-(
 }
 
 
-//elakadtam, mert ne értem a változó argumentumu függvényeket :-(
diff --git a/helloworld/H15_E4.c b/helloworld/H15_E4.c
index a7440e7..fd3e5be 100644
--- a/helloworld/H15_E4.c
+++ b/helloworld/H15_E4.c
@@ -32,7 +32,7 @@ double AddDouble(int x, ...) {
 	for (i=0; i<x; i++) result += va_arg(arglist, double);
 	va_end (arglist);
 return result;
-}
+//na ezzel ugyanaz a problémám, mint az előző feladattal. :-(
+	}
 	
-	//na ezzel ugyanaz a problémám, mint az előző feladattal. :-(
 	
\ No newline at end of file

From ac84e74dcf79e635e79f97664abbf91b243afc84 Mon Sep 17 00:00:00 2001
From: Goodwitch68 on AcerS7 <56366861+Goodwitch68@users.noreply.github.com>
Date: Sat, 9 Nov 2019 08:24:57 +0100
Subject: [PATCH 15/16] Cleanup H16 -H 18

---
 helloworld/H16_E3.c |  4 ++--
 helloworld/H17_E1.c |  6 +++---
 helloworld/H17_E2.c |  6 +++---
 helloworld/H17_E3.c |  2 +-
 helloworld/H17_E4.c | 44 ++++++++++++++++++++------------------------
 helloworld/H18_E3.c | 10 +++++-----
 6 files changed, 34 insertions(+), 38 deletions(-)

diff --git a/helloworld/H16_E3.c b/helloworld/H16_E3.c
index 73d66b5..7a45d90 100644
--- a/helloworld/H16_E3.c
+++ b/helloworld/H16_E3.c
@@ -8,7 +8,7 @@
 void Strprint(char * ch [][15]);
 
 main() {
-	char str[2][15] = { "You know what,", "C is powerful." };
+	char str[2][15] = {"You know what,", "C is powerful."};
 	char *ptr_str;
 	ptr_str = str;
 	Strprint(ptr_str);
@@ -20,6 +20,6 @@ main() {
 
 void Strprint(char *ch [][15]) {
 	printf("%s\n", ch);
+//fordításkor nyom egy csomó warningot, amit nem tudok értelmezni, viszont működik.
 }
 
-//fordításkor nyom egy csomó warningot, amit nem tudok értelmezni, viszont működik.
\ No newline at end of file
diff --git a/helloworld/H17_E1.c b/helloworld/H17_E1.c
index 07da852..150680d 100644
--- a/helloworld/H17_E1.c
+++ b/helloworld/H17_E1.c
@@ -16,13 +16,13 @@ main() {
 	scanf("%d", &SizeofAllmemory);
 	ptr_x = malloc (SizeofAllmemory/2 * sizeof(int));
 	//ptr_x = malloc (SizeofAllmemory); Ez vajon miért nem jó helyette? segmentation faultot ad vissza
-	if (ptr_x != NULL){
-		for (int i = 0; i < SizeofAllmemory/2; i++){
+	if (ptr_x != NULL) {
+		for (int i = 0; i < SizeofAllmemory/2; i++) {
 			ptr_x[i] = i + 1;
 			printf("%d\n", *(ptr_x + i));
 		}
 		printf("Az összeg az elején: %d\n", sum);
-		for (int i = 0; i < SizeofAllmemory/2; i++){
+		for (int i = 0; i < SizeofAllmemory/2; i++) {
 			sum += ptr_x[i];
 			printf("Az összeg most: %d\n", sum);
 		}
diff --git a/helloworld/H17_E2.c b/helloworld/H17_E2.c
index 51dcae9..8ecb077 100644
--- a/helloworld/H17_E2.c
+++ b/helloworld/H17_E2.c
@@ -9,8 +9,8 @@
 main() {
 	float *ptr_x;
 	int result;
-	ptr_x = calloc (100, sizeof(float));
-	if (ptr_x != NULL){
+	ptr_x = calloc(100, sizeof(float));
+	if (ptr_x != NULL) {
 		result = 0;
 		printf("First allocation is done\n");
 	}
@@ -19,7 +19,7 @@ main() {
 		result = 1;
 	}
 	ptr_x = realloc (ptr_x, 150);
-	if (ptr_x != NULL){
+	if (ptr_x != NULL) {
 		result = 0;
 		printf("The reallocation is done\n");
 	}
diff --git a/helloworld/H17_E3.c b/helloworld/H17_E3.c
index 2e836a3..2f161a7 100644
--- a/helloworld/H17_E3.c
+++ b/helloworld/H17_E3.c
@@ -24,7 +24,7 @@ main() {
 		result = 1;
 	}
 	ptr_x2 = calloc (Nodata, sizeof(float));
-	if (ptr_x2 != NULL){
+	if (ptr_x2 != NULL) {
 		result = 0;
 		printf("Second allocation is done\n, the first value of the block is: %f\n", *ptr_x2);
 	}
diff --git a/helloworld/H17_E4.c b/helloworld/H17_E4.c
index ca5531b..db0228f 100644
--- a/helloworld/H17_E4.c
+++ b/helloworld/H17_E4.c
@@ -16,38 +16,34 @@ main() {
 	};
 	char *ptr;
 	int i;
-	
 	int termination = 0;
-	
 	ptr = realloc(NULL, (strlen(str[0]) + 1) * sizeof(char)); //ptr = malloc((strlen(str[0]) + 1) * sizeof(char));
-	if (ptr == NULL){
-	printf("malloc() failed.\n");
-	termination = 1;
-	}
-	else{
-	StrCopy(str[0], ptr);
-	printf("%s\n", ptr);
-	for (i=1; i<4; i++){
-	ptr = realloc(ptr, (strlen(str[i]) + 1) * sizeof(char));
-	if (ptr == NULL){
-	printf("realloc() failed.\n");
-	termination = 1;
-	i = 4; /* break the fro loop */
-	}
-	else{
-	StrCopy(str[i], ptr);
-	printf("%s\n", ptr);
-	}
+	if (ptr == NULL) {
+		printf("malloc() failed.\n");
+		termination = 1;
 	}
+	else {
+		StrCopy(str[0], ptr);
+		printf("%s\n", ptr);
+		for (i=1; i<4; i++) {
+			ptr = realloc(ptr, (strlen(str[i]) + 1) * sizeof(char));
+			if (ptr == NULL) {
+				printf("realloc() failed.\n");
+				termination = 1;
+				i = 4; /* break the for loop */
+			}
+			else {
+				StrCopy(str[i], ptr);
+				printf("%s\n", ptr);
+			}
+		}
 	}
 	realloc(ptr, 0); //free(ptr)
 	return termination;
-	}
+}
 	/* funciton definition */
-	void StrCopy(char *str1, char *str2)
-	{
+	void StrCopy(char *str1, char *str2) {
 	int i;
-	
 	for (i=0; str1[i]; i++)
 	str2[i] = str1[i];
 	str2[i] = '\0';
diff --git a/helloworld/H18_E3.c b/helloworld/H18_E3.c
index f15cce8..3a045d8 100644
--- a/helloworld/H18_E3.c
+++ b/helloworld/H18_E3.c
@@ -2,17 +2,17 @@
 //MIN_NUM instead of the value of MAX_NUM.
 
 #include <stdio.h>
-enum con{MIN_NUM = 0,
-MAX_NUM = 100};
+enum con {MIN_NUM = 0,
+	MAX_NUM = 100};
 int fRecur(int n);
 
 main() {
 	int i, sum1, sum2;
-	
 	sum1 = sum2 = 0;
-	for (i=1; i<=MAX_NUM; i++)
+	for (i=1; i<=MAX_NUM; i++) {
 		sum1 += i;
-		printf("The value of sum1 is %d.\n", sum1);
+	}
+	printf("The value of sum1 is %d.\n", sum1);
 	sum2 = fRecur(MIN_NUM);
 	printf("The value returned by fRecur() is %d.\n", sum2);
 	

From 0079ccfe252f0ee9489e5d9dcf857742fcc3f06d Mon Sep 17 00:00:00 2001
From: Goodwitch68 on AcerS7 <56366861+Goodwitch68@users.noreply.github.com>
Date: Sun, 10 Nov 2019 15:26:52 +0100
Subject: [PATCH 16/16] remove comment

---
 helloworld/H15_E3.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/helloworld/H15_E3.c b/helloworld/H15_E3.c
index 286a822..a443c7a 100644
--- a/helloworld/H15_E3.c
+++ b/helloworld/H15_E3.c
@@ -32,7 +32,7 @@ double AddDouble(int x, ...) {
 	for (i=0; i<x; i++) result += va_arg(arglist, double);
 	va_end (arglist);
 return result;
-//elakadtam, mert nem értem a változó argumentumu függvényeket :-(
+
 }