#include<iostream>
#include<windows.h>
#include<iomanip>
using namespace std;
int number;       //菜單鍵
int year, month, day;   //年、月、日
int i, j, t;       //for循環(huán)用的量
int s;          //星期X
char c;         //存放隨機(jī)輸入的數(shù)字，以實(shí)現(xiàn)“按任意鍵返回主菜單”的功能
char months[] = { 0,31,28,31,30,31,30,31,31,30,31,30,31 };   //平年每個(gè)月的天數(shù)
 
void Pos(int x, int y);   //光標(biāo)位置
void menu();        //主菜單函數(shù)
void runnian();       //如是閏年則變第二個(gè)月天數(shù)28為29
void oneyear();       //輸出一整年的年歷
void onemonth();      //輸出一個(gè)月的月歷
void xianshiweek();     //顯示星期數(shù)
 
void Pos(int x, int y)//光標(biāo)位置 
{
 COORD pos;
 HANDLE hOutput;
 pos.X = x;
 pos.Y = y;
 hOutput = GetStdHandle(STD_OUTPUT_HANDLE);
 SetConsoleCursorPosition(hOutput, pos);
}
void menu()//主菜單函數(shù)
{
 Pos(40, 3);
 cout << "***********************************" << endl;
 Pos(40, 4);
 cout << "*     歡迎使用萬年歷     *" << endl;
 Pos(40, 5);
 cout << "*     ---made by pjr     *" << endl;
 Pos(40, 6);
 cout << "***********************************" << endl;
 Pos(20, 8);
 cout << "操作鍵：" << endl;
 Pos(20, 9);
 cout << "1.顯示一年的年歷" << endl;
 Pos(20, 10);
 cout << "2.顯示一月的月歷" << endl;
 Pos(20, 11);
 cout << "3.顯示某一天是星期幾" << endl;
 Pos(20, 12);
 cout << "0.退出" << endl;
 Pos(20, 14);
 cout << "請輸入操作鍵(0~3):";
 cin >> number;
 if (number < 0 || number>3)
 {
 system("cls");
 Pos(20, 15);
 cout << "輸入數(shù)字無效,請重新輸入!" << endl;
 menu();
 }
}
void runnian()   //如是閏年則變第二個(gè)月天數(shù)28為29
{
 cin >> year;
 if ((year % 4 == 0 && year % 100 != 0) || (year % 400 == 0))   //閏年判斷公式
 {
 months[2] = 29;
 }
}
void oneyear()   //輸出一整年的年歷
{
 cout << "請輸入年份：";
 runnian();
 system("cls");   //清屏
 cout << "請輸入年份：" << year << endl << endl;
 s = (year - 1 + (year - 1) / 4 - (year - 1) / 100 + (year - 1) / 400 + 1) % 7;   //該年1月1日的星期數(shù)
 for (i = 1; i <= 12; i++)
 {
 cout << i << "月份的月歷如下:" << endl;
 cout << setw(6) << "日" << setw(6) << "一" << setw(6) << "二" << setw(6) << "三" << setw(6) << "四" << setw(6) << "五" << setw(6) << "六" << endl;
 for (j = 0; j < s; j++)
 {
  cout << setw(6) << " ";
 }
 for (t = 1; t <= months[i]; t++)
 {
  cout << setw(6) << t;
  s = (s + 1) % 7;
  if (s % 7 == 0)   //當(dāng)打印到星期六時(shí)，換行
  {
  cout << endl;
  }
 }
 cout << endl;
 }
 fflush(stdin);
 cout << "請按任意鍵返回主菜單:";
 cin >> c;
 system("cls");
 menu();
}
void onemonth()//輸出一個(gè)月的月歷
{
 int s = 0;
 cout << "請輸入年份：";
 runnian();
 cout << "請輸入月份：";
 cin >> month;
 system("cls");
 cout << "請輸入年份：" << year << endl << endl;
 cout << "請輸入月份：" << month << endl << endl;
 for (i = 1; i <= month - 1; i++)
 {
 s = s + months[i];   //該年1月1日到所求日期前一天的天數(shù)
 }
 s = (year - 1 + (year - 1) / 4 - (year - 1) / 100 + (year - 1) / 400 + 1 + s) % 7;   //所求日期的星期數(shù)
 cout << month << "月份的月歷如下:" << endl;
 cout << setw(6) << "日" << setw(6) << "一" << setw(6) << "二" << setw(6) << "三" << setw(6) << "四" << setw(6) << "五" << setw(6) << "六" << endl;
 for (j = 0; j < s; j++)
 {
 cout << setw(6) << " ";
 }
 for (t = 1; t <= months[month]; t++)
 {
 cout << setw(6) << t;
 s = (s + 1) % 7;
 if (s % 7 == 0)
 {
  cout << endl;
 }
 }
 cout << endl;
 cout << "請按任意鍵返回主菜單:";
 cin >> c;
 system("cls");
 menu();
}
void xianshiweek()   //顯示星期數(shù)
{
 int s = 0;
 cout << "請輸入年份：";
 runnian();
 cout << "請輸入月份：";
 cin >> month;
 cout << "請輸入日期：";
 cin >> day;
 system("cls");
 cout << "請輸入年份：" << year << endl << endl;
 cout << "請輸入月份：" << month << endl << endl;
 cout << "請輸入日期：" << day << endl << endl;
 for (i = 1; i <= month - 1; i++)
 {
 s = s + months[i];
 }
 s = (year - 1 + (year - 1) / 4 - (year - 1) / 100 + (year - 1) / 400 + day + s) % 7;
 cout << "顯示的星期數(shù)如下:" << s << endl;
 cout << endl;
 cout << "請按任意鍵返回主界面:";
 cin >> c;
 system("cls");
 menu();
}
int main()//主函數(shù)
{
 setlocale(LC_ALL, "chs");//轉(zhuǎn)中文
 menu();
 while (number != 0)
 {
 switch (number)
 {
 case 1:
 {
  oneyear();
  break;
 }
 case 2:
 {
  onemonth();
  break;
 }
 case 3:
 {
  xianshiweek();
  break;
 }
 }
 months[2] = 28; //把months[2]變?yōu)槌踔?
 }
 if (number == 0)
 {
 system("pause");
 }
 return 0;
}