Goldbach's Conjecture map+素数表

#include <stdio.h>#include <cstring>#include <iostream>#include <map>using namespace std;const int maxn=1000001;map <int,int> mp;int p[maxn];bool vis[maxn];int t,n;void get_prime(){    memset(vis,false,sizeof(vis));    memset(p,0,sizeof(p));    t=0;    for(int i=2; i<=maxn; i++)    {        {            for(int j=i*2; j<=maxn; j+=i)                vis[j]=true;        }        if(!vis[i]) p[t]=i,mp[i]=t,t++;    }}int main(){    get_prime();    while(scanf("%d",&n)==1&&n)    {        bool fuck=false;        int ans=0;        for(int i=0; i<t; i++)        {            ans=n-p[i];            if(mp[ans]!=0)            {                fuck=true;                break;            }        }        if(!fuck) printf("Goldbach's conjecture is wrong.\n");        else printf("%d = %d + %d\n",n,n-ans,ans);    }    return 0;}