Submission #1025071

#	Time	Username	Problem	Language	Result	Execution time	Memory
1025071		ByeWorld	Three Friends (BOI14_friends)	C++14	100 / 100	58 ms	6444 KiB

friends

#include <bits/stdc++.h>
// #define int long long
#define ll long long
#define pb push_back
#define fi first
#define se second
using namespace std;
typedef pair<int,int> pii;
typedef pair<int,pii> ipii;
const int MAXN = 2e6+15;
// const int INF = 2e18+10;

int n;
string s;
bool dep=0, bel=0;

signed main(){
	cin >> n;
	cin >> s; s = '.'+s;
	if(n%2==0){ cout << "NOT POSSIBLE\n"; exit(0); }
	int i, j = n/2+1;
	for(i=1; i<=n/2; i++){
		if(s[i]==s[j]) j++;
		else break;
	}
	dep = 1; j++;
	// s[j] blm, s[i] blm
	for(; i<=n/2; i++, j++) 
		if(s[i]!=s[j]) dep = 0;
	j = 1;
	for(i=n/2+2; i<=n; i++){
		if(s[i]==s[j]) j++;
		else break;
	}
	bel = 1; j++;
	for(; i<=n; i++, j++) 
		if(s[i]!=s[j]) bel = 0;

	bool can = 1;
	for(int i=1; i<=n/2; i++){
		if(s[i]!=s[i+n/2+1]) can = 0;
	}
	if(can){ dep = 1; bel = 0; }
	if(!dep && !bel) cout << "NOT POSSIBLE\n";
	else if(dep && bel) cout << "NOT UNIQUE\n";
	else if(dep){
		for(int i=1; i<=n/2; i++) cout << s[i];
		cout << '\n';
	} else {
		for(int i=n/2+2; i<=n; i++) cout << s[i];
		cout << '\n';
	}
}

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