From b40436681ebb4c427fe9fb123e93428506323ca6 Mon Sep 17 00:00:00 2001
From: dhruvil15 <76967484+dhruvil15@users.noreply.github.com>
Date: Tue, 21 Apr 2026 20:03:35 -0400
Subject: [PATCH] Complete20_21

---
 Problem20.java | 25 +++++++++++++++++++++++++
 Problem21.java | 17 +++++++++++++++++
 Sample.java    |  7 -------
 3 files changed, 42 insertions(+), 7 deletions(-)
 create mode 100644 Problem20.java
 create mode 100644 Problem21.java
 delete mode 100644 Sample.java

diff --git a/Problem20.java b/Problem20.java
new file mode 100644
index 00000000..e2d2a01a
--- /dev/null
+++ b/Problem20.java
@@ -0,0 +1,25 @@
+class Solution {
+    public int coinChange(int[] coins, int amount) {
+        int m = coins.length;
+        int n = amount; 
+
+        int[] dp = new int[n+1];
+
+        for (int j = 1; j <= n; j++) {
+            dp[j] = 99999;
+        }
+
+        for (int i = 1; i <= m; i++) {
+            for (int j = 0; j <=n; j++) {
+                if (j < coins[i - 1]) {
+                    dp[j] = dp[j];
+                } else {
+                    dp[j] = Math.min(dp[j], 1 + (dp[j - coins[i-1]]));
+                }
+            }
+        }
+
+        if (dp[n] == 99999) return -1;
+        return dp[n];
+    }
+}
\ No newline at end of file
diff --git a/Problem21.java b/Problem21.java
new file mode 100644
index 00000000..62c06900
--- /dev/null
+++ b/Problem21.java
@@ -0,0 +1,17 @@
+class Solution {
+    public int rob(int[] nums) {
+        int n = nums.length;
+        if (n == 1) return nums[0];
+
+        int prev = nums[0];
+        int curr = Math.max(nums[0], nums[1]);
+
+        for (int i = 2; i < n; i++) {
+            int temp = curr;
+            curr = Math.max(temp, prev+nums[i]);
+            prev = temp;
+        }
+
+        return curr;
+    }
+}
\ No newline at end of file
diff --git a/Sample.java b/Sample.java
deleted file mode 100644
index 1739a9cb..00000000
--- a/Sample.java
+++ /dev/null
@@ -1,7 +0,0 @@
-// Time Complexity :
-// Space Complexity :
-// Did this code successfully run on Leetcode :
-// Any problem you faced while coding this :
-
-
-// Your code here along with comments explaining your approach