1032. Find a Multiple poj 2356 Find a multiple

http://acm.timus.ru/problem.aspx?space=1&num=1032

http://poj.org/problem?id=2356

鸽巢原理

代码:

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
#include<vector>
#include<set>
#include<map>
#include<string>
#include<queue>
#include<stack>
#include <iomanip>
using namespace std;
#define LL long long
#define ULL unsigned long long
const double eps=1e-6;
const int INF=0x3f3f3f3f;
const int N=10003;
int a[N],f[N];
int main()
{
    //freopen("data.in","r",stdin);
    int n;
    cin>>n;
    for(int i=1;i<=n;++i)
    cin>>a[i];
    int tmp=0;
    int l,r;
    memset(f,-1,sizeof(f));
    f[0]=0;
    for(int i=1;i<=n;++i)
    {
        if(a[i]%n==0)
        {cout<<"1"<<endl;cout<<a[i]<<endl;return 0;}
        tmp=(tmp+a[i])%n;
        if(f[tmp]==-1)
        f[tmp]=i;
        else
        {l=f[tmp];r=i;break;}
    }
    cout<<(r-l)<<endl;
    for(int i=l+1;i<=r;++i)
    cout<<a[i]<<endl;
    return 0;
}