撸点代码，或难或易——6

两天写了这么一点东西，推翻好几次，重新来，终于写完了，或许还不是很好，但是加油，还有很多地方可以改

输入一个时间，计算从那天起到现在共过了多少天。

#include<iostream>
#include<time.h>
#include<windows.h>
using namespace std;
int main()
{
	int input_year, input_month, input_day;
	int year, month, day;
	int day_num = 0;
	cout << "请输入年份：";
	cin >> input_year;
	cout << "请输入月份：";
	cin >> input_month;
	cout << "请输入日期：";
	cin >> input_day;
	cout << "你输入的时间是" << input_year << "年" << input_month << "月" << input_day << "日" << endl;
	time_t time1;
	int input_year1 = input_year;
	int input_month1 = input_month;
	int input_day1 = input_day;
	time(&time1);
	struct tm timein;
	localtime_s(&timein, &time1);
	cout << "现在时间是" << timein.tm_year+1900 << "年" << timein.tm_mon+1 << "月" << timein.tm_mday << "日" << endl;
	do
	{
		if (input_year % 400 == 0 || (input_year % 100 != 0 && input_year % 4 == 0))
		{
			switch (input_month)
			{
			case 1:
				day = 31;
				break;
			case 2:
				day = 29;
				break;
			case 3:
				day = 31;
				break;
			case 4:
				day = 30;
				break;
			case 5:
				day = 31;
				break;
			case 6:
				day = 30;
				break;
			case 7:
				day = 31;
				break;
			case 8:
				day = 31;
				break;
			case 9:
				day = 30;
				break;
			case 10:
				day = 31;
				break;
			case 11:
				day = 30;
				break;
			case 12:
				day = 31;
				break;
			}
		}
		else
		{
			switch (input_month)
			{
			case 1:
				day = 31;
				break;
			case 2:
				day = 28;
				break;
			case 3:
				day = 31;
				break;
			case 4:
				day = 30;
				break;
			case 5:
				day = 31;
				break;
			case 6:
				day = 30;
				break;
			case 7:
				day = 31;
				break;
			case 8:
				day = 31;
				break;
			case 9:
				day = 30;
				break;
			case 10:
				day = 31;
				break;
			case 11:
				day = 30;
				break;
			case 12:
				day = 31; 
				break;
			}
		}
		if (input_day > day)
		{
			input_month++;
			input_day = 1;
			if (input_month > 12)
			{
				input_year++;
				input_month = 1;
				input_day = 1;
			}
			else
			{
				input_day = 1;
			}
		}
		else 
		{
			input_day++;
			day_num = day_num + 1;
		}
	} while (input_year!= timein.tm_year + 1900 || input_month != timein.tm_mon + 1 || input_day != timein.tm_mday);
	cout << "从" << input_year1 << "年" << input_month1 << "月" << input_day1 << "日到今天共" << day_num << "天" << endl;
	system("pause");
}