请评价一上这段代码

请评价一下这段代码
题目:给出年月日,算出当天是这一年的第几天.

#include <stdio.h>

int main()
{
int year,month,day
//输入年月日
printf("输入年月日,以空格隔开即可");
scanf("%d%d%d",&year,&month,&day);
//计算天数
switch( month-1 )
{
case 12: day+=31;
case 11: day+=30;
case 10: day+=31;
case 9: day+=30;
case 8: day+=31;
case 7: day+=31;
case 6: day+=30;
case 5: day+=31;
case 4: day+=30;
case 3: day+=31;
//闰年判定
case 2: day += (year%4==0 && year%100!=0 || year%400==0) ? 29 : 28;
case 1: day+=31
default: break;
}

//输出结果
printf("这是今年第%d天",day);
}

------解决方案--------------------
少了输入的合法性检测！
------解决方案--------------------

C/C++ code

#include <stdio.h>

int main(void)
{
    int y, m, d, i, days = 0;
    int months[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30 };
    scanf("%d%d%d", &y, &m, &d);
    if ((y % 4 == 0 && y % 100 != 0) || (y % 400 == 0))
        ++months[1];
    for (i = 0; i < m - 1; ++i)
        days += months[i];
    days += d;
    printf("%d", days);
    return 0;
}

------解决方案--------------------

探讨
这是在被要求用switch做出这题写的.

修复如下:
#include <stdio.h>

int main()
{
int year,month,day;
//输入年月日
while(TRUE)
{
printf("输入年月日,以空格隔开即可");
scanf("%d%d%d",&year,&month,&day);
if( mo……

------解决方案--------------------

探讨

引用:

依题意来看，这代码根本就错了嘛。

"当天"这个词看来有歧义?可题目就是这么说的,可以指输入的日期,也可以指程序运行的当天,我认为是前一种意思.

------解决方案--------------------

C/C++ code


//计算天数
switch( month-1 )
{
  case 10:
  case 12: 
  case 8:
  case 7:
  case 5:
  case 3:
  case 1:
      day+=31;
      break;
  case 11:
  case 9:
  case 6:
  case 4: 
      day+=30;
      break;
  //闰年判定
  case 2: 
      day += (year%4==0 && year%100!=0 || year%400==0) ? 29 : 28;
      break;
  default: 
      break;
}

------解决方案--------------------
switch没必要吧

C/C++ code


#include <stdio.h>
int main()
{
    int y,m,d,ms[]={0,31,28,31,30,31,30,31,31,30,31,30,31},ds[]={0,0,31,59,90,120,151,181,212,243,273,304,334};
    goto BEGIN;
    
AGAIN:
    printf("Illegal date! Please input again!\n");
BEGIN:
    printf("Please input a date(format: 2012-7-19): ");
    scanf("%d-%d-%d", &y, &m, &d);
    if(0 >= m)                        goto AGAIN;
    if(12 < m)                        goto AGAIN;
    if(ms[m]+((0==y%4)&&(2==m)) < d)goto AGAIN;
    
    printf("The day of the year is: %d.\n", ds[m]+d+((0==y%4)&&(2<m)));
    return 0;
}

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