#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#define Maxn 1000005

int prime[80000];
bool f[Maxn];
int pt;

void fact()
{
    int i, j;
    pt = 0;
    memset(f, false, sizeof(f));
    for(i = 4;i <= 1000000;i += 2){
        f[i] = true;
    }
    f[0] = f[1] = f[2] = true;
    for(i = 3;i <= 1000000;i++){
        if(f[i] == false){
             prime[pt++] = i;
             if(i > 1000)continue;
             j = i * i;
             while(j <= 1000000){
                    f[j] = true;
                    j += i;
            }
        }
    }
}

int main()
{
    fact();
    int n, tag, i, a, b; 
    while(scanf("%d", &n) && n){
        tag = 0;
        for(i = 0;i < pt;i++){
            if(prime[i] >= n || n - prime[i] < prime[i]) break;
            if(f[n - prime[i]] == false && n - prime[i] != prime[i]){
                a = prime[i];
                tag = 1;
                break;
            }
        }
        if(tag == 0){
            printf("Goldbach's conjecture is wrong.\n");
            continue;
        }
        b = n - a;
        printf("%d = %d + %d\n", n, a, b);
    }
}

• Do you really think goldbach's conjecture is wrong when n == 6 ? (1278) MicroGoogle 2007-10-17 21:16:45