percentage difference of variables

[LEHCAR95]

hi can someone help - when i calculate the percentage different of the actual number and the approximate number (calculating farenheit when knowing celsius) with this formula it always returns 0? cant seem to work it out

x=0;
	for (x>=0; x<=100; x++)
	{
		approx = (x*2)+30;
		actual = (x*9.5)+32;
		diff = actual-approx;
		pdiff = (((actual-approx)/actual)*100);

		
		cout << x << "\t" << approx << "\t" << actual << "\t" << diff << "\t" << "\t" << pdiff << "\n";
	}

[wildblue]

How do you have your variables defined? Sounds like you might be running into integer division giving you result of 0. I defined them as double and the output works with the rest of your code.

#include <iostream>
using namespace std;

int main() {

double approx,actual,diff,pdiff;

for (int x=0; x<=100; x++)
	{
		approx = (x*2)+30;
		actual = (x*9.5)+32;
		diff = actual-approx;
		pdiff = (((actual-approx)/actual)*100);

		
		cout << x << "\t" << approx << "\t" << actual << "\t" << diff << "\t" << "\t" << pdiff << "\n";
	}
	return 0;
}

0	30	32	2		6.25
1	32	41.5	9.5		22.8916
2	34	51	17		33.3333
3	36	60.5	24.5		40.4959
4	38	70	32		45.7143
5	40	79.5	39.5		49.6855
6	42	89	47		52.809
7	44	98.5	54.5		55.3299
8	46	108	62		57.4074
9	48	117.5	69.5		59.1489
10	50	127	77		60.6299

...

97	224	953.5	729.5		76.5076
98	226	963	737		76.5317
99	228	972.5	744.5		76.5553
100	230	982	752		76.5784

[LEHCAR95]

thanks!