perf test

// CPerf.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

int forloop_inf(int loops, int iterations)
{
	int n = 0;
	int x = n;

	for (int l = 0; l < loops;l++) {
		for (int i = 0; i < iterations;i++) {
			n++;
			x += n;
		}
	}

	return x;
}

int forloop_diff(int loops, int iterations)
{
	int n = 0;
	int x = n;

	for (int l = 0; l != loops;l++) {
		for (int i = 0; i != iterations;i++) {
			n++;
			x += n;
		}
	}

	return x;
}

double monitor(int loops, int iterations, int(*func)(int, int), int *result)
{
	clock_t start = clock();

	*result = func(loops, iterations);

	clock_t stop = clock();

	return (double)(stop - start) / CLOCKS_PER_SEC;
}

typedef int(loop_signature)(int, int);

void loops_compare()
{
	int loops = 1 * 100;
	int iterations = 1000 * 1000;
	int result;

	loop_signature *functions[2] = {
		forloop_diff,
		forloop_inf
	};

	int n_rand = 1000;

	int n[2] = { 0, 0 };
	double cum[2] = { 0.0, 0.0 };

	for (int i = 0; i < n_rand;i++) {
		int pick = rand() % 2;
		loop_signature *fun = functions[pick];

		double time = monitor(loops, iterations, fun, &result);
		n[pick]++;
		cum[pick] += time;
	}

	printf("'!=' %f (%d) / '<' %f (%d)\n", cum[0] / (double)n[0], n[0], cum[1] / (double)n[1], n[1]);
}

int main()
{
	loops_compare();

	char c;
	scanf_s("\ndone%c", &c, 1);

	return 0;
}