#include<stdio.h>
#include<math.h>
#include<stdlib.h>
#include<time.h>

//                           每月天数 

int month_day(int year,int month)
{
	switch(month)
        {
            case 1:
            case 3:
            case 5:
            case 7:
            case 8:
            case 10:
            case 12:
            return 31;break;
            
            case 4:
            case 6:
            case 9:
            case 11:
            return 30;break; 

            case 2:
            	if((year%4==0)&&(year%100!=0)||(year%400==0))
            	{
            		return 29;
            		break;
				}
				else
				{
					return 28;
					break;
				}
		}
}


//                       年历
                                         
void year_calendar(int year)
{
	int month,days,weekday,sum_day;
	int i,j;
    
		year;
		printf("请输入要查询的年份：");
		scanf("%d",&year); 
	for(i=1;i<year;i++)
	{
		if((year%4==0)&&(year%100!=0)||(year%400==0))
		  sum_day+=366;
		else
		  sum_day+=365;	
	}
		for(month=1;month<=12;month++)
		{
		    printf("\n--------%d/%d--------\n",year,month);
            printf("SUN\tMON\tTUE\tWED\tTHU\tFRI\tSAT\t\n");
            i=1;
            j=1;
			weekday=sum_day%7;
			while(i<=weekday)              //开始位置前都是空格 
			{
				printf("\t");
				i++;
			}
			while(j<=month_day(year,month))
			{
				weekday=sum_day%7;
				if (weekday==6)
					printf("%d\n",j);
					
				else			
					printf("%d\t",j);	

				if(j==month_day(year,month))
				    printf("\n");
				
				j++;
				sum_day++;	
			}
		 } 
}


//                        月历 

void month_calendar(int year,int month)
{
	int sum_day=0,weekday,i,j,k;
	printf("请输入要查询的年/月：");
	scanf("%d/%d",&year,&month); 
	for(i=1;i<year;i++)
	{
		if((year%4==0)&&(year%100!=0)||(year%400==0))
		  sum_day+=366;
		else
		  sum_day+=365;	
	}
	for(k=1;k<month;k++)
	{
	    sum_day+=month_day(year,month);
	}

		    printf("\n\t--------%d/%d--------\n",year,month);
            printf("\tSUN\tMON\tTUE\tWED\tTHU\tFRI\tSAT\t\n");
            i=1;
            j=1;
			weekday=sum_day%7;
			while(i<=weekday)              //开始位置前都是空格 
			{
				printf("\t");
				i++;
			}
			while(j<=month_day(year,month))
			{
				weekday=sum_day%7;
				if (weekday==6)
					printf("%d\n",j);
					
				else			
					printf("%d\t",j);	

				if(j==month_day(year,month))
				    printf("\n");
				
				j++;
				sum_day++;	
			} 
}

//                                   距今多少天 
void Time(int year,int month,int day)

{
    time_t t;//将t声明为时间变量 
    struct tm *p;//struct tm是一个结构体，声明一个结构体指针
    time(&t);
    p=localtime(&t);//获得当前时间 
    int now_year,now_month,now_day;
    now_year=1900+p->tm_year;
    now_month=1+p->tm_mon;
    now_day=p->tm_mday;
    printf("当前日期是：%d/%d/%d\n",now_year,now_month,now_day);
    //输入日期的总天数 
    int i,k,sum_day;
    printf("请输入要查询的年/月/日：");
	scanf("%d/%d/%d",&year,&month,&day); 
	for(i=1;i<year;i++)
	{
		if((year%4==0)&&(year%100!=0)||(year%400==0))
		  sum_day+=366;
		else
		  sum_day+=365;	
	}
	for(k=1;k<month;k++)
	{
	    sum_day+=month_day(year,month);
	}
	sum_day+=day;
    //当前总日期 
    int j,sum_nowday;
    for(j=1;j<now_year;j++)
	{
		if((now_year%4==0)&&(now_year%100!=0)||(now_year%400==0))
		  sum_nowday+=366;
		else
		  sum_nowday+=365;	
	}
	for(k=1;k<now_month;k++)
	{
	    sum_nowday+=month_day(now_year,now_month);
	}
	sum_nowday+=now_day;
	//相减得差值

	if(sum_day>sum_nowday)
	  printf("\n输入日期与当前日期相差%d天",sum_day-sum_nowday);
    else
      printf("\n输入日期与当前日期相差%d天",sum_nowday-sum_day);
    
}

//日期查询

void rq(int year,int month,int day)
{
	printf("请输入要查询的年/月/日：");
	int sum_day,i,k,weekday; 
	scanf("%d/%d/%d",&year,&month,&day); 
	for(i=1;i<year;i++)
	{
		if((year%4==0)&&(year%100!=0)||(year%400==0))
		  sum_day+=366;
		else
		  sum_day+=365;	
	}
	for(k=1;k<month;k++)
	{
	    sum_day+=month_day(year,month);
	}
	sum_day+=day;
	weekday=sum_day%7;
	printf("\n");
	switch(weekday)
	{
		case 0:
			{
			printf("星期日"); 
			break;
		    }
		case 1:
			{
			printf("星期一"); 
			break;
		    }
		case 2:
			{
			printf("星期二"); 
			break;
		    }
		case 3:
			{
			printf("星期三");
			break;
		    }
		case 4:
			{
			printf("星期四");
			break;
		    }
		case 5:
			{
			printf("星期五");
			break;
		    }
		case 6:
			{
			printf("星期六"); 
			break;
		    }
	}
	
	printf("\n\n");
	if(month==1)
	{
		if(day==1)
		  printf("元旦");
	}
	else if(month==2)
	{
		if(day==14)
		  printf("情人节"); 
	}
	else if(month==3)
	{
		switch(day)
		{
			case 8:printf("妇女节");break;
			case 12:printf("植树节");break;
		}
	}
	else if(month==4)
	{
		if(day==1)
		  printf("愚人节"); 
	}
	else if(month==5)
	{
		switch(day)
		{
			case 1:printf("劳动节");break;
			case 4:printf("青年节");break;
		}
	}
	else if(month==6)
	{
		if(day==1)
		  printf("儿童节"); 
	}
	else if(month==7)
	{
		if(day==1)
		  printf("建党节"); 
	}
	else if(month==8)
	{
		if(day==1)
		  printf("建军节"); 		
	} 
	else if(month==9)
	{
		if(day==10)
		  printf("教师节");
	}
	else if(month==10)
	{
		if(day==1)
		  printf("国庆节"); 
	}
	else if(month==11)
	{
		;
	}
	else
	{
		if(day==25)
		  printf("圣诞节");
	}
}

int main(void)
{
	printf("\n-------------------选择服务-------------------\n\n");
	printf("                   1.年历显示\n");
	printf("                   2.月历显示\n");
	printf("                   3.距今多少天\n");
	printf("                   4.日期查询\n");
	printf("                   5.退出\n");
	printf("\n-------------------选择服务-------------------\n") ;
	
	int n,year,month,day;
	printf("请选择服务：");
	scanf("%d",&n);
	switch(n)
	{
		case 1:
			{
				year_calendar(year);
				break;
			}
		case 2:
			{
				month_calendar(year,month);
				break;
			}
		case 3:
			{
				Time(year,month,day);
				break;
			}
		case 4:
			{
				rq(year,month,day);
				break;
			}
		case 5:
			{
				return 0;
			}
	}
}