日历

import java.util.*;
 class demo2 
{
    public static void main(String[] args) 
    {
      System.out.println("---------日历------------");
        Scanner input =new Scanner(System.in);
        System.out.println("输入年份");
        int year = input.nextInt();
        System.out.println("输入月份");
        int month = input.nextInt();
        int sumDay=0;
        int monthDay=0;
    for(int i=1900;i<year;i++) 
   {     
        sumDay+=365;
        if(month==2){   
            monthDay=28;  
        } else {  
        if(month==4||month==6||month==9||month==11){
            monthDay=30; 
            }else{ 
            monthDay=31; 
            }
        }
    }
    for(int i=1;i<month;i++){ 
       if(i==2){    
     if(year%4==0&&year%100!=0||year%400==0){   
        sumDay+=29;
        }else{ 
    sumDay+=28;
    }
} else { 
   if(i==4||i==6||i==9||i==11){ 
       sumDay+=30; 
       }else{
    sumDay+=31;
    } 
   }   
    }
    

    System.out.println("一共有"+sumDay+"天");
  
   //计算month月的第一天为周 几
   int weekday =(sumDay+1)%7;
   System.out.println(weekday);

   System.out.println("星期天\t星期一\t星期二\t星期三\t星期四\t星期五\t星期六");

   for(int a = 0;a<weekday;a++){
    System.out.print("\t");
   }

   for(int b=1; b<=monthDay;b++){
    System.out.print(b+"\t");
    if(( b+weekday)%7 ==0)
        System.out.println();
   }

}

    }