输入年月日输出此日是此年的第几天

输入年月日

输出此日是此年的第几天

程序1

#include"stdafx.h"
#include<iostream>
using namespace std;
#define YEARERROR -2
#define MONTHERROR -1
#define DAYERROR -3

bool Is_Leap(int year)
{
	return (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0);
}
int YearMonth_To_Day(int year, int month)
{
	if (year < 1) return YEARERROR;
	if (month < 1 || month > 12) return MONTHERROR;
	//int total_day[]={0,31,59,90,120,151,181,21,243,273,304,334}; 
	//total = total_day[month - 1] + day + (month >= 2 && Is_Leap(year));
	int days[13] = { 29, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };         
	if (month == 2 && Is_Leap(year))
	{
		month = 0;
	}
	return days[month];
}

int YearMonthDays_To_total(int year,int month,int days)
{
	int total=0;
	if (year < 1) return YEARERROR;
	if (month < 1 || month > 12) return MONTHERROR;
	if (days < 1 || days>31)return DAYERROR; 
	int mday = YearMonth_To_Day(year, month);
	for (int i = 1; i < month; ++i)
	{
		total = total + YearMonth_To_Day(year, i);
	}
	total = total + days;
	return total;
}
int main()
{
	int year, month, days;
	int total;
	char ch;
	for (;;)
	{ 
		cout << "input year month days:";
		cin >> year >> month >> days;
		total = YearMonthDays_To_total(year, month, days);
		switch (total)
		{
		case YEARERROR:cout << "intput year is error!" << endl; break;
		case MONTHERROR:cout << "intput year is error!" << endl; break;
		case DAYERROR:cout << "intput year is error!" << endl; break;
		default:cout << year << " year " << month << " month " << days << " days=> ";
			cout << total << endl;
			break;
		}
		cout << "Y继续，N退出" << endl;
		cin >> ch;
		if (ch == 'N' || ch == 'n')break;
	}
	return 0;

程序2

#include"stdafx.h"
#include<iostream>
using namespace std;
#define YEARERROR -2
#define MONTHERROR -1
#define DAYERROR -3
	int Month[13] = { 29, 31, 28, 31, 30, 31, 30,31, 31, 30, 31, 30 ,31};
	bool Year(int year)
	{return ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0);}
	int YearMonth_days(int year, int month)
	{
		int day;
		if (month == 2 && Year(year)）{day = Month[0];}
		else{day = Month[month];}
		return day;
	}
	int YearMonth_total(int year, int month, int days)
	{
		int total, M_month=0, D_days;
		if (year < 1)return YEARERROR;
		if (month < 1 || month>12)return MONTHERROR;
		D_days = YearMonth_days(year, month);
		if (days < 1 || days>D_days)return DAYSERROR;
		if (12>=month&&month>2)
		{
			for (int i = 1; i < month; i++)
			{M_month += Month[i];}
			total = days + M_month + Year(year);
		}
		else if (month > 1){total = Month[1] + days; return total; }
		else{ total = days;return total;}
	    return total;
	}
	int main()
	{
		int year, month,days,total;
		char ch;
		for (;;)
		{
		cout << "请输入年月日：\n";
		cin >> year >> month>>days;
		total = YearMonth_total(year, month, days);
		switch (total)
		{
		case YEARERROR:cout << "输入年份有误,请重新输入：\n"; break;
		case MONTHERROR:cout << "输入月份有误,请重新输入：\n"; break;
		case DAYSERROR:cout << "输入日有误,请重新输入：\n"; break;
		default:cout <<"此日为此年的"<< total << "天" << endl; break;
		}
	     cout << "继续请按Y，退出请按N:\n";
		 cin >> ch;
			if (ch =='N'|| ch == 'n')break;
		}
		return 0;
	}

运行结果：