Submission #1265916

#	Time	Username	Problem	Language	Result	Execution time	Memory
1265916		canhnam357	Three Friends (BOI14_friends)	C++20	100 / 100	11 ms	8168 KiB

friends

// source problem : 
#include <bits/stdc++.h>
using namespace std;
#define all(x) x.begin(), x.end()
#define int long long
#define lb lower_bound
#define ub upper_bound
#define MASK(i) (1LL << (i))
const int inf = 1e18;
void ckmax(int& f, int s)
{
    f = (f > s ? f : s);
}
void ckmin(int& f, int s)
{
    f = (f < s ? f : s);
}
bool in(string s, string t)
{
    int j = 0;
    for (int i = 0; i < s.size() && j < t.size(); i++)
    {
        if (s[i] == t[j]) j++;
    }
    return j == t.size();
}
int32_t main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n;
    string s;
    cin >> n >> s;
    if (n % 2 == 0)
    {   
        cout << "NOT POSSIBLE";
        return 0;
    }
    int m = n / 2;
    string a = s.substr(0, m), b = s.substr(m);
    string c = s.substr(0, m + 1), d = s.substr(m + 1);
    if (in(b, a))
    {
        if (in(c, d))
        {
            if (a != d) cout << "NOT UNIQUE";
            else cout << a;
        }
        else cout << a;
    }
    else
    {
        if (in(c, d))
        {
            cout << d;
        }
        else cout << "NOT POSSIBLE";
    }
    return 0;
}

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