C语言十进制转2进制数

#include <stdio.h>
#include <math.h>

long toBinary(int num);

int main(int argc, char const *argv[])
{
	int num;
	printf("Please input a number: ");
	scanf("%d", &num);

	long binnary = toBinary(num);

	printf("%d\n", binnary);

	return 0;
}

long toBinary(int num) {
	short count = 0;
	short i;
	long ret = 0;
	short nums[64];
	
	while(num) {
		nums[count++] = num % 2;
		num = num / 2;
	}

	for(i = count - 1; i >= 0; i--) {
		ret += pow(10, i) * nums[i];
	}

	return ret;
}