//求一个数的绝对值
#include <stdio.h>
int absolute_value(int num)
{
	if (num < 0)
	{
		num = ~(num - 1);
	}
	return num;
}
int main()
{
	printf("%d\n", absolute_value(5));
	printf("%d\n", absolute_value(-5));
	printf("%d\n", absolute_value(0));
	return 0;
}