POJ.2739 Sum of Consecutive Prime Numbers(水)

POJ.2739 Sum of Consecutive Prime Numbers(水)

代码总览

#include <cstdio>
#include <cstring>
#include <vector>
#include <cmath>
#define nmax 10005
using namespace std;
int prime[nmax],n;
vector<int> vprime;
void init()
{
    memset(prime,0,sizeof(prime));
    int up = sqrt(nmax)+1;
    for(int i = 2;i<=up;++i){
        if(prime[i] == 0)
            for(int j = 2;i*j<=nmax;++j){
                prime[i*j] = 1;//not prime
            }
    }
    for(int i = 2; i<=nmax;++i){
        if(prime[i] == 0){
            //printf("%d\n",i);
            vprime.push_back(i);
        }
    }

}

int main()
{
    //freopen("in.txt","r",stdin);
    //freopen("out.txt","w",stdout);
    init();
    while(scanf("%d",&n) !=EOF && n){
        int ans = 0;
        int total = 0;
        for(int i = 0;i<vprime.size();++i){
            total = vprime[i];
            if(vprime[i] == n){
                ans++;
                break;
            }else if(vprime[i]>n) break;
            for(int k = i+1;k<vprime.size();++k){
                total += vprime[k];
                if(total == n) ans++;
                else if(total>n) break;
            }
        }
        printf("%d\n",ans);
    }
    return 0;
}