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;}
