#include <stdio.h>
#include<stdlib.h> 
#include <conio.h> 
void Output_Menu();                       /*輸出菜單*/ 
void Output_Calendarofyear();             /*輸出輸入年份的日歷*/
void Output_Calendarofmonth();            /*輸出輸入月份的日歷*/
void Leapyear_Judgement();                /*判斷輸入年份是不是閏年*/
void Getweek_Ofdate();                    /*計算輸入某年某月中某一日是星期幾*/
int Getdayamount_Ofyear(int);             /*計算輸入年份的天數*/
int Getdayamount_Ofmonth(int,int) ;       /*計算輸入年份是月份的天數*/
void Getdaysamount_Ofmonth();             /*輸出輸入年份是月份的天數*/
int Getweek_Firstdayofyear(int);          /*計算每年第一天是星期幾*/
int Getweek_Firstdayofmonth(int,int);     /*計算每月第一天是星期幾*/
int Week(int,int,int);                    /*求出星期對應的數字如（4對應星期四）*/
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void main()
{
   char menu; 
   do   
   { 
	 system("cls");
     Output_Menu(); 
	 scanf("%s",&menu);
     switch(menu)  
	 { 
       case '1': Getweek_Ofdate();  break; 
       case '2': Leapyear_Judgement(); break; 
       case '3': Output_Calendarofyear(); break; 
	   case '4': Getdaysamount_Ofmonth();break;
       case '5': Output_Calendarofmonth();break; 
	   case '6': break;
       default:printf("輸入錯誤,按任何鍵返回.\n");getch();break;
     }
   } while(menu!=6);  
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void Output_Menu()/*輸出主菜單*/
{ 
   printf("1:----------我想知道某一天是星期幾\n"); 
   printf("\n");
   printf("2:----------我想知道某年是不是閏年\n"); 
   printf("\n");
   printf("3:----------我想瀏覽一下某年的日歷\n"); 
   printf("\n");
   printf("4:----------我想知道某個月有多少天\n"); 
   printf("\n");
   printf("5:----------我想瀏覽一下某月的日歷\n");
   printf("\n");
   printf("6:----------我不想做其中的任何操作\n");
   printf("\n");
   printf("請選擇你想做的操作:"); 
} 
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void Output_Calendarofyear()/*輸出某一年十二個月的日歷*/
{
   int month=0,i,j,year;
   char continueflag; 
   do
   {
      printf("請輸入年份(xxxx)=>");
      scanf("%d",&year);
      int w=Getweek_Firstdayofmonth(year,month);
      char *p[7]={"  Sun","  Mon","  Tue","  Wed","  Thu","  Fri","  Sat"};
      for(month=1;month<=12;month++)
	  {
         printf("\n*************** %d ****************\n\n",month);
         for(i=0;i<7;i++) printf("%s",*(p+i));
         printf("\n");
         for(i=0;i<w;i++) printf("     ");   /*輸出空格*/
         for(j=1;j<=Getdayamount_Ofmonth(year,month);j++)
		 {
            printf("%5d",j);                 /*輸出每天的日期*/
            w++;
            w=w%7;
            if(w==0&&j<=Getdayamount_Ofmonth(year,month)) printf("\n");
		 }
	  }
      printf("\n是否繼續<Y繼續,其它鍵返回>");
      continueflag=getch(); 
      printf("%c\n",continueflag); 
   } while (continueflag=='y' || continueflag=='Y'); 
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void Output_Calendarofmonth() /*輸出某一年中某月的日歷*/
{
   int month,year,i,j;
   char continueflag;
   do
   { 
      printf("請輸入年份(xxxx)=>");
      scanf("%d",&year);
      printf("請輸入月份(xx)=>");
      scanf("%d",&month);
      int w=Getweek_Firstdayofmonth(year,month);
      char *p[7]={"  Sun","  Mon","  Tue","  Wed","  Thu","  Fri","  Sat"};
      printf("\n*************** %d ****************\n\n",month);
      for(i=0;i<7;i++) printf("%s",*(p+i));
      printf("\n");
      for(i=0;i<w;i++) printf("     ");      /*輸出空格*/
      for(j=1;j<=Getdayamount_Ofmonth(year,month);j++)
	  {
         printf("%5d",j);                    /*輸出每一天的日期*/
         w++;
         w=w%7;
         if(w==0&&j<=Getdayamount_Ofmonth(year,month)) printf("\n");
	  }
      printf("\n是否繼續<Y繼續,其它鍵返回>");
      continueflag=getch(); 
      printf("%c\n",continueflag); 
   } while (continueflag=='y' || continueflag=='Y'); 
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void Leapyear_Judgement()/*判斷輸入年份是不是閏年*/
{   
	int year;
    char continueflag; 
	do
	{
	   printf("請輸入年份(xxxx)=>");
	   scanf("%d",&year);
   	   if(year%4==0&&year%100!=0||year%400==0) 
		  printf("你輸入的年份就是閏年!!!");
       else 
	      printf("你輸入的年份不是閏年!!!");
	   printf("\n是否繼續<Y繼續,其它鍵返回>");
       continueflag=getch(); 
       printf("%c\n",continueflag); 
	} while (continueflag=='y' || continueflag=='Y'); 
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void Getweek_Ofdate()/*求某年某月某日是星期幾*/
{
	int year,month,date,weekday; 
    char continueflag; 
    char *weekdaystr; 
    do
	{ 
       printf("請輸入年份(xxxx)=>"); 
       scanf("%d",&year); 
       printf("請輸入月份(xx)=>");
       scanf("%d",&month); 
       printf("請輸入日期(xx)=>");
       scanf("%d",&date);
       weekday=Week(year,month,date); 
       switch(weekday) 
	   { 
          case 0:   weekdaystr="日"; break; 
          case 1:   weekdaystr="一"; break; 
          case 2:   weekdaystr="二"; break; 
          case 3:   weekdaystr="三"; break; 
          case 4:   weekdaystr="四"; break; 
          case 5:   weekdaystr="五"; break; 
          case 6:   weekdaystr="六"; break; 
	   } 
       printf("%d年%d月%d日是星期%s，是否繼續<Y繼續,其它鍵返回>",year,month,date,weekdaystr); 
       continueflag=getch(); 
       printf("%c\n",continueflag); 
	}while(continueflag=='y' || continueflag=='Y'); 
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   
int Getdayamount_Ofyear(int year)/*計算輸入年份的天數*/
{
   int days;
   if(year%4==0&&year%100!=0||year%400==0) days=366;
   else days=365;
   return days;
}
int Getdayamount_Ofmonth(int year,int month)/*計算每月的天數*/
{
   int monthdays;
   switch(month)
   {
      case 2:monthdays=(Getdayamount_Ofyear(year)==366)? 29:28;
          break;                
      case 1:
      case 3:
      case 5:
      case 7:
      case 8:
      case 10:
      case 12:monthdays=31;
          break;         
      case 4:
      case 6:
      case 9:
      case 11:monthdays=30;
          break;         
   }
   return monthdays;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

void Getdaysamount_Ofmonth()/*計算每月的天數*/
{
   int monthdays,year,month;
   char continueflag; 
   do
   {
      printf("請輸入年份(xxxx)=>");
      scanf("%d",&year);
      printf("請輸入月份(xx)=>");
      scanf("%d",&month);
      switch(month)
	  {
      case 2:monthdays=(Getdayamount_Ofyear(year)==366)? 29:28;
          break;                
      case 1:
      case 3:
      case 5:
      case 7:
      case 8:
      case 10:
      case 12:monthdays=31;
          break;         
      case 4:
      case 6:
      case 9:
      case 11:monthdays=30;
          break;         
	  }
      printf("%d",monthdays);
      printf("\n是否繼續<Y繼續,其它鍵返回>");
      continueflag=getch(); 
      printf("%c\n",continueflag); 
   }while(continueflag=='y' || continueflag=='Y'); 
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

int Getweek_Firstdayofyear(int year)/*計算每年第一天星期幾*/
{
   int sum=0,firstday,i;
   if(year>=2000)
   {
      for(i=2000;i<year;i++) sum=Getdayamount_Ofyear(i)+sum;
      firstday=(sum+6)%7;
   }
   else
   {
      for(i=year;i<2000;i++) sum=Getdayamount_Ofyear(i)+sum;
      firstday=(6-sum%7)%7;
   }
   return firstday;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

int Getweek_Firstdayofmonth(int year,int month)/*計算每月第一天是星期幾*/
{
   int month_day,sum=0,i;
   for(i=1;i<month;i++)
   {
      sum=sum+Getdayamount_Ofmonth(year,i);
   }
   month_day=(Getweek_Firstdayofyear(year)+sum)%7;
   return month_day;
}
//%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

int Week(int year,int month,int date)/*應用基姆拉爾森計算公式求星期*/
{
	if((month==1)||(month==2))  
	{ 
      month+=12; 
      year--; 
    } 
    return int((date+2*month+3*(month+1)/5+year+year/4-year/100+year/400)+1)%7; 
}