输入某年某月某日，判断这一天是这一年的第几天?(考虑闰年的情况)public class Day1 {
    public static void main(String[]args){
    System.out.println("请输入某年:");
    Scanner in = new Scanner(System.in);
    int year = in.nextInt();
    System.out.println("请输入某月:");
     int month = in.nextInt();
     System.out.println("请输入某日:");
    int day = in.nextInt();
    int arr1[] = {31,28,31,30,31,30,31,31,30,31,30,31};//非闰年
    int arr2[] = {31,29,31,30,31,30,31,31,30,31,30,31};//闰年
     int tian = 0;
    int zhengyue = 0;
      if(year%100!=0&&year%4 == 0){
     if(month<2){
     System.out.println(year+"年"+month+"月"+day+"日是今年的第"+day+"天"); }
else
{
       for(int i = 2;i <= month;i++)
{ zhengyue += arr2[i-2];  }
     tian = zhengyue + day;
     System.out.println(year+"年"+month+"月"+day+"日是今年的第"+tian+"天");}
    }
else{
         if(month<2)
{ System.out.println(year+"年"+month+"月"+day+"日是今年的第"+day+"天");  }
else{  for(int i = 2;i <= month;i++)
{
                    zhengyue += arr1[i-2];
                    }
    tian = zhengyue + day;
    System.out.println(year+"年"+month+"月"+day+"日是今年的第"+tian+"天");

            }
        }
    }
}

输入某年某月某日，判断这一天是这一年的第几天?(考虑闰年的情况)public class Day1 {
    public static void main(String[]args){
    System.out.println("请输入某年:");
    Scanner in = new Scanner(System.in);
    int year = in.nextInt();
    System.out.println("请输入某月:");
     int month = in.nextInt();
     System.out.println("请输入某日:");
    int day = in.nextInt();
    int arr1[] = {31,28,31,30,31,30,31,31,30,31,30,31};//非闰年
    int arr2[] = {31,29,31,30,31,30,31,31,30,31,30,31};//闰年
     int tian = 0;
    int zhengyue = 0;
      if(year%100!=0&&year%4 == 0){
     if(month<2){
     System.out.println(year+"年"+month+"月"+day+"日是今年的第"+day+"天"); }
else
{
       for(int i = 2;i <= month;i++)
{ zhengyue += arr2[i-2];  }
     tian = zhengyue + day;
     System.out.println(year+"年"+month+"月"+day+"日是今年的第"+tian+"天");}
    }
else{
         if(month<2)
{ System.out.println(year+"年"+month+"月"+day+"日是今年的第"+day+"天");  }
else{  for(int i = 2;i <= month;i++)
{
                    zhengyue += arr1[i-2];
                    }
    tian = zhengyue + day;
    System.out.println(year+"年"+month+"月"+day+"日是今年的第"+tian+"天");

            }
        }
    }
}