程序4

/*
【程序4】
题目：输入某年某月某日，判断这一天是这一年的第几天？
【分析】
1 定义出每月的天数（递增）
2 然后根据输入的月份确定前面的总天数
3 加上剩下的天数
另一个问题：当为瑞年时，且月份大于2应该加1
*/
#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>

int main(int argc, int **argv){
	int year = 0, month = 0, day = 0;
	int sum = 0;
	printf("请输入年月日（格式为：2018 9 12）\n");
	scanf("%d %d %d", &year, &month, &day);
	switch (month)
	{
	case 1:sum = 0; break;
	case 2:sum = 31; break;
	case 3:sum = 59; break;
	case 4:sum = 90; break;
	case 5:sum = 120; break;
	case 6:sum = 151; break;
	case 7:sum = 181; break;
	case 8:sum = 212; break;
	case 9:sum = 243; break;
	case 10:sum = 273; break;
	case 11:sum = 304; break;
	case 12:sum = 334; break;
	default:printf("data error"); break;
	}
	sum += day;
	if ((year % 400 == 0) || ((year % 4 == 0) && (year % 100 != 0)))
	{
		if (month > 2)
		{
			sum += 1;
		}
	}
	printf("%d年%d月%d日为%d年的第%d天\n", year, month, day, year, sum);
	return 0;
}







#if 0
【程序4】
题目：输入某年某月某日，判断这一天是这一年的第几天？
1.程序分析：以3月5日为例，应该先把前两个月的加起来，然后再加上5天即本年的第几天，特殊情况，闰年且输入月份大于3时需考虑多加一天。
2.程序源代码：
main()
{
int day,month,year,sum,leap;
printf("\nplease input year,month,day\n");
scanf("%d,%d,%d",&year,&month,&day);
switch(month)/*先计算某月以前月份的总天数*/
{ case 1:sum = 0; break;
case 2:sum = 31; break;
case 3:sum = 59; break;
case 4:sum = 90; break;
case 5:sum = 120; break;
case 6:sum = 151; break;
case 7:sum = 181; break;
case 8:sum = 212; break;
case 9:sum = 243; break;
case 10:sum = 273; break;
case 11:sum = 304; break;
case 12:sum = 334; break;
default:printf("data error"); break; }
sum = sum + day; 　/*再加上某天的天数*/
if (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0))/*判断是不是闰年*/
leap = 1;
else
leap = 0;
if (leap == 1 && month > 2)/*如果是闰年且月份大于2,总天数应该加一天*/
sum++;
printf("It is the %dth day.", sum); }
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#endif