Language-Engineering/testd.le at master · ethangk/Language-Engineering · GitHub

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{Program to find square root of an integer}
{use 43 as data }
begin
    write('Recommended input:'); writeln;
    write('43.0'); writeln; writeln;

    guess:=0.0;            		{first guess at answer}
    inc:=1.0;            		{guess increment}
    write('Square root.');
    writeln;
    write('Enter number: ');
    read(n);
    writeln;
    if n<0.0           		{No root if number is <0}
    begin
        write('No real root exists.');
        writeln;
    end
    else
    begin
        repeat		    		{while increment is not too small}
        begin

	    repeat		  	{while guess^2 is too small}
            begin
                guess:=guess+inc;    	{increase guess by increment}
            end
            until guess*guess >= n; {repeat}

	    if guess*guess=n       {if guess was right}
            begin                	{do nothing}
            end
            else
            begin
                guess:=guess-inc;    	{else go back to last
                            		 guess that was
                            		 smaller than right
                            		 answer}
            end;    {if}
            inc:=inc/2.0;            	{halve increment then loop again}
        end
	until inc<0.0001; {repeat}

        write('(Approximate) answer: ');
        write(guess);
        writeln;
    end; {if}
end