B - Aesthetics in poetry

B - Aesthetics in poetry

 Gym - 101879B 

题意：

N个数 找一个n的因数k然后 这n个数取余k得到n-1种结果。

另一个要求是这n种取余结果出现的次数得=n/k。

. We say that the poem is KK-elegant if K>1K>1, NN is a multiple of KK and, moreover, there are exactly N/KN/K verses whose sizes, when divided by KK, have remainders equal to ii, for i=0,1,…,K−1i=0,1,…,K−1. Note that a single poem may be KK-elegant for several distinct values of KK.

#include<iostream>
#include<string>
#include<cstring>
#include<iomanip>
#include<queue>
#include<stack>
#include<map>
#include<vector>
#include<algorithm>
#include<stdio.h>
#include<cmath>
using namespace std;
# define maxn 25000
# define inf 0x3f3f3f3f
long long n,a[maxn],m;
map<long long,int>mmp;
int main()
{
    bool flag=0;
    cin>>n;
    for(int i=0; i<n; i++)
        cin>>a[i];
    for(int i=2; i<=n; i++)
    {
        if(n%i==0)
        {

            mmp.clear();
            for(int j=0; j<n; j++)
            {
                mmp[a[j]%i]++;
            }
            if(mmp.size()==i)
            {
                bool f=0;
                for(int j=0; j<i; j++)
                {
                    if(mmp[j]!=n/i)
                    {
                        f=1;
                        break;
                    }
                }
                if(f==0)
                {
                    flag=1;
                    cout<<i<<endl;
                    break;
                }
            }
        }
    }
    if(flag==0)
        cout<<-1<<endl;
    return 0;
}