C语言计算日期天数差_天真与无邪的博客_c语言日期差

#include <stdio.h>
int add(int y,int m,int d) 
{
	int i,k=0;
	int sun=0;
	if (y%4==0 && y%100==0 ||y%400==0) 
	{
		for (i=0;i<m;i++)
		{
			int arr[12] = { 31,29,31,30,31,30,31,31,30,31,30,31 };
			k += arr[i];
		}
	}
	else
	{
		for (i = 0; i < m; i++)
		{
			int arr[12] = { 31,28,31,30,31,30,31,31,30,31,30,31 };
			k += arr[i];
		}
	}
	sun = (y - 1) / 4 + y * 365 + k;
	return sun;
}
int main()
{
	int year1=0, month1=0, day1=0;
	int year2=0, month2=0, day2=0;
	int num1=0, num2=0;
	printf("请输入第一个日期");
	scanf_s("%d %d %d",&year1,&month1,&day1);
	num1 = add(year1,month1,day1);
	num1 = num1 + day1;

	printf("请输入第一个日期");
	scanf_s("%d %d %d",&year2,&month2,&day2);
	num2 = add(year2, month2, day2);
	num2 = num2 + day2;

	if (num1<num2)
	{
		printf("%d",num2-num1);
	}
	else
	{
		printf("%d",num1-num2);
	}
}
#include <stdio.h>
int add(int y,int m,int d)