循环控制：（第10题）与闰年相关的问题，涉及数组，函数的知识

#include <stdio.h>
int is_leap_year(int year)
{
	if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)
		return 1;
	else
		return 0;
}
int gap_years(int year)
{
	int i = 1990;
	int sum = 0;
	int gap_years = 0;
	if (year == 1990)
		return 0;
	for (i = 1990; i < year; i++)
	{
		if (is_leap_year(i))
			gap_years = 366;
		else
			gap_years = 365;
		sum += gap_years;
	}
	return sum;
}
int gap_months(int year,int month)
{
	int days[] = { 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
	int days_in_leap_year[] = { 0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };
	int sum=0;
	int i = 0;
	if (month == 1)
		return 0;
		if (is_leap_year(year))
		{
			for (i = 1; i < month ; i++)
			{
				sum += days_in_leap_year[i];
			}
			return sum;
	    }
		else
		{
			for (i = 1; i < month ; i++)
			{
				sum += days[i];
			}
			return sum;
		}
}
int main()
{
	int day = 0;
	int month = 0;
	int year = 0;
	int gap = 0;
	int a = 0;
	scanf("%4d-%2d-%2d", &year, &month, &day);
	if (day >= 32)
	{
		printf("Invalid input");
	}
	else
	{
		gap = gap_years(year) + gap_months(year, month) + day;
		printf("%d\n", gap);
		a = gap % 5;
		printf("%d\n", gap_years(year));
		printf("%d\n", gap_months(year, month));
		printf("%d\n", day);
		if (a <= 3 && a > 0)
			printf("He is working");
		else
			printf("He is having a rest");
	}
	return 0;
}