UVA 543
任何大于4的偶数都能写成sum of two odd prime number ,只要从小开始逐一判断,然后写出最大和最小的组合就可以了
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
1 #include<stdio.h> 2 #include<math.h> 3 int prime(int a) 4 { 5 int i,flag=1; 6 for(i=2;i<=sqrt(a);i++) 7 { 8 if(a%i==0) 9 { 10 flag=0; 11 break; 12 } 13 } 14 return flag; 15 } 16 int main() 17 { 18 int n,a,flag; 19 while(scanf("%d",&n)&&n) 20 { 21 flag=0; 22 for(a=2;a<=n/2;a++) 23 { 24 if(prime(a)&&prime(n-a)) 25 { 26 flag=1; 27 break; 28 } 29 } 30 if(flag==0) 31 printf("Goldbach's conjecture is wrong.\n"); 32 else 33 printf("%d = %d + %d\n",n,a,n-a); 34 } 35 return 0; 36 }