Codeforces Round #563 (Div. 2)A

A. Ehab Fails to Be Thanos

Topic links: http://codeforces.com/contest/1174/problem/A

topic

You’re given an array a of length 2n. Is it possible to reorder it in such way so that the sum of the first n elements isn’t equal to the sum of the last n elements?

Input
The first line contains an integer n(1≤n≤1000), where 2n is the number of elements in the array a.
The second line contains 2n space-separated integers a1, a2, …, a2n (1≤ai≤106) — the elements of the array a

Output
If there’s no solution, print “-1” (without quotes). Otherwise, print a single line containing 2n
space-separated integers. They must form a reordering of a. You are allowed to not change the order

The meaning of problems

2n give you an array of length a, reorder, and after the first n such that the sum of n elements not want to wait, -1 if not sort output, the output can be re-sorted array of length 2n a.

Thinking

First determine whether a number of the same array, if the same can not be sorted before the number n and it is not the sum of the number n, the output 1;

Otherwise, after obtaining the first n and the number n, it is determined whether they are equal, if they are equal, then the order of the output to a sort, and the like directly do not want the original inverted output to a array.

 

//
// Created by hjy on 19-6-4.
//

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
const int maxn=2e5+10;
int main()
{
    int n;
    while(cin>>n)
    {
        int a[maxn];
        int x;
        cin>>x;
        a[0]=x;
        int flag=a[0];
        int num=1;
        for(int i=1;i<2*n;i++)
        {
            cin>>a[i];
            if(a[i]==flag)
                num++;
        }
        if(num==2*n)
            cout<<"-1"<<endl;
        else
        {
            int l=accumulate(a,a+n,0);
            cerr<<"l="<<l<<endl;//cerr对提交无影响

            int r=accumulate(a+n,a+2*n,0);
            cerr<<"r="<<r<<endl;
            if(l!=r) {
                for(int i=0;i<2*n;i++)
                {
                    cout<<a[i]<<' ';
                }
                cout<<endl;
            } else
            {
                sort(a,a+2*n);
                for(int i=0;i<2*n;i++)
                    cout<<a[i]<<' ';
                cout<<endl;
            }

        }

    }
    return 0;
}