[Java] 练习题014: 输入某年某月某日，判断这一天是这一年的第几天？

【程序14】
题目：输入某年某月某日，判断这一天是这一年的第几天？
1.程序分析：以3月5日为例，应该先把前两个月的加起来，然后再加上5天即本年的第几天，特殊情况，闰年且输入月份大于3时需考虑多加一天。   import java.util.*;
public class Test014
{
  public static void main(String[] args) throws Exception
  {
    int y,m,d;
    int sum=0;
    int feb=28;
    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");
  }
}