Submission #1263513

#	Time	Username	Problem	Language	Result	Execution time	Memory
1263513		bruhhhh	Three Friends (BOI14_friends)	C++20	0 / 100	9 ms	9212 KiB

friends

#include <bits/stdc++.h>
using namespace std;
int main(){
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(nullptr);
    long long n;
    string s;
    cin >> n >> s;
    if((n - 1) % 2){
        cout << "NOT POSSIBLE";
        return 0;
    }
    long long k = (n - 1) / 2;
    long long l = 0, r = k + 1;
    while(l < k && s[l] == s[r]){
        l++; 
        r++;
    }
    vector<long long> cands;
    if(l == k){
        cands.push_back(k);
    } else {
        cands.push_back(l);
        cands.push_back(r);
    }
    long long cnt = 0;
    string answer;
    set<string> seen;
    cands.push_back(n - 1);
    for(long long i : cands) {
        if(i < 0 || i >= n) continue;
        string t = s.substr(0, i) + s.substr(i + 1);
        if(t.substr(0, k) == t.substr(k)) {
            string half = t.substr(0, k);
            if(seen.count(half)) continue;
            seen.insert(half);
            cnt++;
            if(cnt > 1) {
                cout << "NOT UNIQUE";
                return 0;
            }
            answer = half;
        }
    }
    if(cnt == 0)
        cout << "NOT POSSIBLE";
    else
        cout << answer;
    return 0;
}

• Subtask 1: 0 / 35
• Subtask 2: 0 / 65