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;

}