Submission #73094209

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Source Code Expand

#include <bits/stdc++.h>
#include <algorithm>
using namespace std;

#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
#endif

struct Init { Init() { ios::sync_with_stdio(0); cin.tie(0); } }init;

using ll = long long;
using ull = unsigned long long;
using pii = pair<int,int>;
using pll = pair<ll,ll>;
#define rep(i,l,r) for (ll i = (ll)l; i < (ll)r; i++)


int main(){
    Init();
    ll N;
    cin >> N;
    vector<ll> A(N);
    rep(i,0,N){
        cin >> A[i];
    }
    sort(A.begin(), A.end());
    if(N>2){
        auto Iter = lower_bound(A.begin(), A.end() ,A[N-1]);

        //最大長がそのまま残るパターン
        int upper = Iter - A.begin() - 1; // 最大の一個前の値を指すインデックス
        int i=0;
        int is_ok = false;

        if(upper % 2 !=0){
            while(true){
                if(i >= upper - i){
                    if(upper)
                    is_ok = true;
                    break;
                }  
                if(A[N-1] != A[i] + A[upper - i]) break;
                i++;
            }
        }
        //最大長が変わるパターン

        ll x = A[0] + A[N-1];
        i=0;
        bool is_ok_2 = false;
        while(true){
            if(i >= N-i){
                // Nが奇数のときは中間の値をそのまま比較する
                if(N%2==1){
                    if(x != A[N/2]) break;
                }
                is_ok_2 = true;
                break;
            }
            if(x != A[i] + A[N-i-1]){
                break;
            }
            i++;
        }
        string out = "";
        if(is_ok){
            out += to_string(A[N-1]);
        }

        if(is_ok_2){
        if(is_ok){ out += " ";}
            out += to_string(x);
        }

        cout << out << endl;
    }
    else if(N==2){
        if(A[0] == A[1]){
            cout << to_string(A[0]) + " ";
        }
        cout << A[0] + A[1] << endl;
    }
    else{
        cout << A[0] << endl;
    }
}

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