>     #include<stdio.h> 
> 
>     int main() 
>     { 
>         int p, e, i, d; 
>         int j, days, x; 
> 
>         scanf( "%d%d%d%d", &p, &e, &i, &d ); 
>         j = 0; 
>         while( p != -1 || e != -1 || i != -1 || d != -1 ) 
>         { 
>             j++; 
>             for( x = i; ; x += 33 ) 
>             { 
>                 if(x >d && x >= p && x >= e && x >= i && (x-p)%23 == 0 && (x-e)%28 == 0 && (x-i)%33 == 0 ) 
>                 { 
>                     days = x % 21252 ; 
>                     break; 
>                 } 
>             } 
> 			days -= d;
> 			if(days<=0) days +=21252;
>            /* if( x > 21252 ) 
>                 days = 21252-d; */
>             printf( "Case %d: the next triple peak occurs in %d days.\n", j, days ); 
>                     scanf( "%d%d%d%d", &p, &e, &i, &d ); 
>         } 
>     } 
> 改成这样可以ac,但运行时间要很长,最好直接找出规律