Submission #105693

#	Time	Username	Problem	Language	Result	Execution time	Memory
105693		sams	Three Friends (BOI14_friends)	C++14	0 / 100	210 ms	7904 KiB

friends

#include <bits/stdc++.h>

using namespace std;

int n;
string u;
map<char, int> ct;

int main()
{
	cin >> n >> u;

	if(n % 2 == 0)
	{
		cout << "NOT POSSIBLE\n";
		return 0;
	}
	
	for(auto x: u) ct[x]++;
	
	int I = 0;
	char rep = '.';
	for(auto x: ct)
		if(x.second % 2)
			I++, rep = x.first;

	if(I > 1)
	{
		cout << "NOT POSSIBLE\n";
		return 0;
	}
	
	int mid = (n-1)/2;
	
	string s1, s2;

	int ok = 2;
	int id = -1;
	for(int i = 0 ; i < mid ; ++i) s1.push_back(u[i]);
	for(int i = mid ; i < n ; ++i) s2.push_back(u[i]);
	
	for(int i = 0, j = 0, k = 0; i < mid ; ++j, ++i)
	{
		if(s1[i] != s2[j]) 
		{	if(k == 0 && s1[i] == s2[j+1]) id = j, j++, k = 1;
			else
			{
				ok--;
				id = -1;
				break;
			}
		}
	}

	s1.clear(); s2.clear();

	for(int i = 0 ; i <= mid ; ++i) s2.push_back(u[i]);
	for(int i = mid + 1 ; i < n ; ++i) s1.push_back(u[i]);
	
	/* for(int i = 0 ; i < s2.size() ; ++i) cout << s2[i];
	cout << "\n";
	for(int i = 0 ; i < s1.size() ; ++i) cout << s1[i];
	*/
	for(int i = 0, j = 0, k = 0; i < mid ; ++j, ++i)
	{
		if(s1[i] != s2[j]) 
		{	if(k == 0 && s1[i] == s2[j+1]) id = j, j++, k = 1;
			else
			{
				ok--;
				id = -1;
				break;
			}
		}
	}

	if(ok == 0) cout << "NOT POSSIBLE\n";
	else if(ok == 1 || ct[rep] == n)
	{	
		if(id <= mid && id != -1) mid++;

		for(int i = 0 ; i < mid ; ++i) if(i != id) cout << u[i];
		cout << "\n";
	}else cout << "NOT UNIQUE\n";
	return 0;
}

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