Submission #930836

#	Time	Username	Problem	Language	Result	Execution time	Memory
930836		Wendidiask	Three Friends (BOI14_friends)	C++14	100 / 100	100 ms	17064 KiB

friends

/*
  ____       _      _                  _                    _               _                        _     _                  _          _____ _     _             
 |  _ \     (_)    | |                (_)                  | |             (_)                      | |   | |                (_)        / ____| |   (_)            
 | |_) | ___ _  ___| |__   ___ _ __    _ ___    __ _    ___| | __ _ ___ ___ _  ___   _ __  _ __ ___ | |__ | | ___ _ __ ___    _ _ __   | |    | |__  _ _ __   __ _ 
 |  _ < / _ \ |/ __| '_ \ / _ \ '_ \  | / __|  / _` |  / __| |/ _` / __/ __| |/ __| | '_ \| '__/ _ \| '_ \| |/ _ \ '_ ` _ \  | | '_ \  | |    | '_ \| | '_ \ / _` |
 | |_) |  __/ | (__| | | |  __/ | | | | \__ \ | (_| | | (__| | (_| \__ \__ \ | (__  | |_) | | | (_) | |_) | |  __/ | | | | | | | | | | | |____| | | | | | | | (_| |
 |____/ \___|_|\___|_| |_|\___|_| |_| |_|___/  \__,_|  \___|_|\__,_|___/___/_|\___| | .__/|_|  \___/|_.__/|_|\___|_| |_| |_| |_|_| |_|  \_____|_| |_|_|_| |_|\__,_|
                                                                                    | |                                                                            
                                                                                    |_|                                                                            
*/
#include <bits/stdc++.h>
using namespace std;
#define int long long
#define debug(x) cerr << #x << " is " << x << "\n";
#define hehe ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
#define rep(i, a, b) for (int i = a; i <= b; i++)
#define repb(i, a, b) for (int i = b; i >= a; i--)
#define pii pair<int, int>
#define linebreak cout << "---------------------------------------------------------\n"
// good luck
const int MS = 2e6+5;
int n, cnt[26], a[MS];
char letter[] = {'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z'};
int32_t main() {
	memset(cnt, 0, sizeof(cnt));
	cin >> n;
	for (int i = 1; i <= n; i++) {
		char temp;
		cin >> temp;
		a[i] = temp-'A';
	}
	if (n%2 == 0) {
		cout << "NOT POSSIBLE\n"; return 0;
	}
	int m = n/2;
	// answer either lies in either half
	int left = 1, right = 1, x = m+1;
	for (int i = 1; i <= m; i++) {
		while (a[i] != a[x] and x <= n) x++; 
		if (x >= n+1) {
			left = 0; break;
		}
		x++;
	}
	x = 1;
	for (int i = m+2; i <= n; i++) {
		while (a[i] != a[x] and x <= m+1) x++; 
		if (x >= m+2) {
			right = 0; break;
		}
		x++;
	}
	if (left == 0 and right == 0) {
		cout << "NOT POSSIBLE\n";
		return 0;
	}
	if (left == 1 and right == 1) {
		for (int i = 1; i <= m; i++) {
			if (a[i] != a[i+m+1]) {
				cout << "NOT UNIQUE\n";
				return 0;
			} 
		}
		for (int i = 1; i <= m; i++) cout << letter[a[i]];
	}
	if (left == 1 and right == 0) {
		for (int i = 1; i <= m; i++) cout << letter[a[i]];
		return 0;
	}
	if (right == 1 and left == 0) {
		for (int i = m+2; i <= n; i++) cout << letter[a[i]];
		return 0;
	}
	
}

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