Submission #398840

#	Time	Username	Problem	Language	Result	Execution time	Memory
398840		Hassan61	Three Friends (BOI14_friends)	C++14	0 / 100	56 ms	6192 KiB

friends

/**
 * pair : first second
 * binary : lower_bound    upper_bound
 * strings : tolower    toupper
 * vector : push_back erase begin
 * set : insert
**/

/*
#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
*/

#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define un unsigned
#define MAXN 200004
ll n, a, b, r, x1, x2;
string str;
int main()
{
	//ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
	cin >> n >> str;
	if (n % 2 == 0) {
		cout << "NOT POSSIBLE";
		return 0;
	}
	int sSize = n / 2 + 1;
	string s1(sSize, 'a'), s2(sSize,'a'), s3(sSize-1, 'a');
	int j = 0;
	for (int i = 0; i <= n/2; i++)
	{
		s1[j] = str[i];
		j++;
	}
	j = 0;
	for (int i = n/2; i < n; i++)
	{
		s2[j] = str[i];
		j++;
	}
	x1 = x2 = r = 0;
	for (int i = 0; i <= n / 2; i++)
	{
		if (s1[i+x1]==s2[i+x2]) {
			r++;
			//cout << s1[i + x1] << " " << s2[i + x2] << "\n";

		}
		else if (i!= n / 2) {
			if (x1 + x2 == 0 && s1[i + 1] == s2[i]) {
				x1 = 1;
				r++;
				//cout << s1[i + x1] << " " << s2[i + x2] << "\n";

			}
			else if (x1 + x2 == 0 && s1[i] == s2[i + 1]) {
				x2 = 1;
				r++;
				//cout << s1[i + x1] << " " << s2[i + x2] << "\n";

			}
			else if (s1[i + 1] == s2[i + 1]) {
				x1 = x2 = 1;
				r++;
				//cout << s1[i + x1] << " " << s2[i + x2] << "\n";

			}
		}
		

		if(i< n / 2)s3[i] = s1[i + x1];
		if (x1 + x2 > 0 && i == n / 2-1)break;

	}

	if (r == sSize) {
		cout << "NOT UNIQUE";

	}
	else if (r + 1 == sSize) {
		
		cout << s3;

	}
	else {
		cout << "NOT POSSIBLE";
	}
}

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