Submission #1126423

#	Time	Username	Problem	Language	Result	Execution time	Memory
1126423		Agageldi	Three Friends (BOI14_friends)	C++20	100 / 100	17 ms	8248 KiB

friends

/*
ID: agageld1
LANG: C++17
TASK:
*/
#include <bits/stdc++.h>
using namespace std;

#define ll long long
#define N 400005
#define ff first
#define ss second
#define pb push_back
#define sz(s) (int)s.size()
#define rep(c, a, b) for(c = a; c <= b; c++)

//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

ll n, t, a[N], p = 0;
string s, g, ans;
void solve(string h) {
	int cnt = 0, tr = 0;
	for(int i = 0; i < sz(s); i++) {
		if(cnt == sz(h)) break;
		if(h[cnt] == s[i]) cnt++;
		else {
			tr++;
			if(tr == 2)	break;
		}
	}
	if(tr <= 1) p = 1;
}

int main () {
	ios::sync_with_stdio(0);cin.tie(0);
	cin >> n >> s;
	if(n % 2 == 0) {
		cout << "NOT POSSIBLE";
		return 0;
	}
	for(int i = 0; i < n/2; i++) {
		g += s[i];
	}
	int f = 0;
	solve(g + g);
	if(p) {
		ans = g;
		f++;
	}
	g = "";
	for(int i = n/2 + 1; i < n; i++) {
		g += s[i];
	}
	p = 0;
	solve(g + g);
	if(p) {
		if(sz(ans) == 0 || ans != g){
			ans = g;
			f++;
		}
	}
	if(!f) cout << "NOT POSSIBLE\n";
	if(f == 2) cout << "NOT UNIQUE\n";
	else cout << ans << '\n';
}

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