输入某年某月某日，判断这一天是这一年的第几天。

代码：

package com.liron.p1;

import java.util.Scanner;

/**
 * 输入某年某月某日，判断这一天是这一年的第几天。
 */
public class Topic4 {
    public static void main(String[] args) throws Exception  
    {  
        int y,m,d;  
        int sum=0;  
        int feb=28;  
        @SuppressWarnings("resource")
        Scanner in = new Scanner(System.in);  
        System.out.print("请输入年份:");  
        y = in.nextInt();  
        System.out.print("请输入月份:");  
        m = in.nextInt();  
        System.out.print("请输入几号:");  
        d = in.nextInt();  
          
        if((y%4==0 && y%100!=0) || y%400==0)  
        {  
            feb = 29;  
        }  
          
        switch(m)  
            {  
                    case 1:  
                        sum = d;  
                        break;  
                    case 2:  
                        sum = 31 + d;  
                        break;  
                    case 3:  
                        sum = 31+feb+d;  
                        break;  
                    case 4:  
                        sum = 31+feb+31+d;  
                        break;  
                    case 5:  
                        sum = 31+feb+31+30+d;  
                        break;  
                    case 6:  
                        sum = 31+feb+31+30+31+d;  
                        break;  
                    case 7:  
                        sum = 31+feb+31+30+31+30+d;  
                        break;  
                    case 8:  
                        sum = 31+feb+31+30+31+30+31+d;  
                        break;  
                    case 9:  
                        sum = 31+feb+31+30+31+30+31+31+d;  
                        break;  
                    case 10:  
                        sum = 31+feb+31+30+31+30+31+31+30+d;  
                        break;  
                    case 11:  
                        sum = 31+feb+31+30+31+30+31+31+30+31+d;  
                        break;  
                    case 12:  
                        sum = 31+feb+31+30+31+30+31+31+30+31+30+d;  
        }  
        System.out.println(y+" 年 "+m+" 月 " + d + "号是今年的第"+sum+"天");  
    }
}

结果：