Submission #520693

#	Time	Username	Problem	Language	Result	Execution time	Memory
520693		sidon	Three Friends (BOI14_friends)	C++17	100 / 100	57 ms	4612 KiB

friends

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

string s;
int n, p;

bool match(int i, int j) {
	for(int k = p = 0; k <= n; k++)
		p += p < n && s[i+p] == s[j+k];

	return p == n;
}

int main() {
	cin >> n >> s; s += '$';

	bool L = match(0, n/=2), R = match(n+1, 0);

	if((!L && !R) || size(s) & 1) return !(cout << "NOT POSSIBLE");

	if(L && R && !match(0, n+1)) cout << "NOT UNIQUE";
	else cout << s.substr(R*(n+1), n);
}

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