【案例描述】

以下程序輸入年月日，輸出該日是本年中的第幾天。請將代碼補充完整。

main()

{ struct{int y,m,d;}(   );

  int n;

  scanf("%4d%2d%2d",&day.y,&day.m,&day.d);

  n=day.d+(day.m-1)*30;

  n+=day.m/2+(day.m==9)+(day.m==11);

  if(day.m>2)

    if(day.y%400==0||(day.y%4==0 && day.y%100))(    );else (   );

  printf("%d",n);}

【案例分析】

以上代碼的求解思路是：

1、先假定每月30天，計算總天數：n=day.d+(day.m-1)*30

2、再加上大月天數：day.m/2+(day.m==9)+(day.m==11)

3、再根據是否為閏年修正2月的天數。

【參考代碼】

main()

{ struct{int y,m,d;}day;

  int n;

  scanf("%4d%2d%2d",&day.y,&day.m,&day.d);

  n=day.d+(day.m-1)*30;

  n+=day.m/2+(day.m==9)+(day.m==11);

  if(day.m>2)

     if(day.y%400||(day.y%4==0 && day.y%100))n-=1;else n-=2;

  printf("%d",n);

}