已知一个日期和天数， 求多少天后的日期（是那个超时代码的AC版)

 #include <stdio.h>
 #include <string.h>
 int m2 = ;
 int judge_year(int x)
 {

         if(x %  ==  || x %  ==  && x %  != )
             return ;
         else
             return ;

 }

 //extern int m2;
 int calculate_year(int *x, int y)
 {

         //extern int m2 = ;//出现 cannot initialize extern variables with block scope错误，即不能在块作用域里声明全局变量

         int span = ;
         while(*x - span >= ){

                 y++;/*天数满一年加1*/
                 *x -= span;/*减去今年的天数*/
                 span = judge_year(y) ?  : ;/*判断下一年的天数*/

         }
         m2 = judge_year(y) ?  : ;/*判断几天后2月份的天数*/
         return y;

 }
 //extern int m2;
 int calculate_month(int *x, int m)
 {

         int span = ;
         while(*x - span >= ){

                 m++;
                 *x -= span;
                 if(m ==  || m ==  || m ==  || m ==  || m ==  || m ==  || m == )
                 {

                         span = ;

                 }
                 else if(m ==  || m ==  || m ==  || m == )
                 {

                         span = ;

                 }
                 else
                 {

                         span = m2;

                 }

         }
         return m;

 }

 extern int m2;
 int main()
 {

         int year = , month = , day = , L_year, L_month, sum, X_sum;
         char s[];
         //int m2=29;
         while(scanf("%d", &sum) && sum != -){

                 day = ;
                 X_sum = sum;
                 L_year = calculate_year(&sum, year);
                 L_month = calculate_month(&sum, month);
                 day += sum;
                 switch(X_sum % )
                 {

                         case : strcpy(s, "Friday"); break;
                         case : strcpy(s, "Saturday"); break;
                         case : strcpy(s, "Sunday"); break;
                         case : strcpy(s, "Monday"); break;
                         case : strcpy(s, "Tuesday"); break;
                         case : strcpy(s, "Wednesday"); break;
                         case : strcpy(s, "Thursday"); 

                  }
                 printf("%d-", L_year);
                 if(L_month <= )
                     printf("0%d-", L_month);
                 else
                     printf("%d-", L_month);
                 if(day <= )
                     printf("0%d ", day);
                 else
                     printf("%d ", day);
                 printf("%s\n", s);
             //    printf("%d %d %d\n", L_year, m2, L_month);

         }
         return ;

 }

一个学姐路过，看到我的代码，认为没有那么麻烦，于是自己写了一个，

 #include <stdio.h>
 #include <string.h>
 int judge_year(int x)
 {

         if(x %  ==  || x %  ==  && x %  != )
             return ;
         else
             return ;

 }
 int main()
 {
     int year = , month = , day = ,sum,week,i;
     int ans[]={,,,,,,,,,,,},a[]={,};
     char s[][]={"Saturday","Sunday","Monday","Tuesday","Wednesday","Thursday","Friday"};
     while(scanf("%d", &sum) && sum != -)
     {
         week=sum%;
         year = , month = , day = ;
         while(sum>=a[judge_year(year)])
         {
             sum-=a[judge_year(year)];
             year++;
         }
         if(judge_year(year))
             ans[]=;
         else
             ans[]=;
         for(i=;i<;i++)
         {
             if(sum>=ans[i])
             {
                 sum-=ans[i];
                 month++;
             }
             else
                 break;
         }
         day+=sum;
         printf("%4d-%02d-%02d %s\n",year,month,day,s[week]);
     }
     return ;
 }

跟我的执行时间等等一样，但长度明显短了许多。