> #include<stdio.h> 
> #define MAX 1000001 
> int prime[MAX]={0};  
> void sushu() 
> { 
>     int i,j; 
>     for(i=2;i<MAX;i++) 
>         if(!prime[i]) 
>             for(j=2;i*j<MAX;j++) //j因该从i开始，可以减少不少循环次数
>                 prime[j*i]=1;
>     prime[0] = prime[1] = 1;  
> } 
> int main() 
> { 
>     int n,i; 
>     sushu(); 
>     while (scanf("%d",&n)==1,n)  
>     { 
>         for(i=3;i<=n/2;i+=2)  
>             if(prime[i]==0&&prime[n-i]==0) 
> 			{
>                 printf("%d = %d + %d\n", n, i, n-i); 
>                 break; 
> 			}
>         if(i>n/2) 
>             printf("Goldbach's conjecture is wrong.\n"); 
>     } 
>     return 0; 
> }