Submission #380424

#	Time	Username	Problem	Language	Result	Execution time	Memory
380424		BeanZ	Three Friends (BOI14_friends)	C++14	100 / 100	34 ms	7148 KiB

friends

// I_Love_LPL
#include <bits/stdc++.h>
using namespace std;
#define ll long long
#define endl '\n'
const int N = 2e5 + 5;
long long mod = 1e9 + 7;
const int lim = 2e5;
const int lg = 19;
const int base = 311;
const long double eps = 1e-6;
ll n;
string s;
string chk(ll l1, ll r1, ll l2, ll r2){
    bool flag = false;
    string t;
    for (int i = l1; i <= r1; i++){
        if (s[i] == s[l2]){
            l2++;
        } else if (s[i] == s[l2 + 1] && !flag){
            l2 += 2;
            flag = true;
        } else {
            return "-1";
        }
    }
    for (int i = l1; i <= r1; i++) t.push_back(s[i]);
    return t;
}
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    if (fopen("tests.inp", "r")){
        freopen("tests.inp", "r", stdin);
        freopen("tests.out", "w", stdout);
    }
    cin >> n;
    cin >> s;
    s = " " + s;
    if ((n % 2) == 0) return cout << "NOT POSSIBLE", 0;
    string one = chk(1, n / 2, n / 2 + 1, n);
    string two = chk(n / 2 + 2, n, 1, n / 2 + 1);
    if (one == "-1" && two == "-1") return cout << "NOT POSSIBLE", 0;
    if (one != "-1" && two != "-1" && one != two) return cout << "NOT UNIQUE", 0;
    if (one == "-1") return cout << two, 0;
    else return cout << one, 0;

}
/*
Ans:

Out:
*/

Compilation message (stderr)

friends.cpp: In function 'int main()':
friends.cpp:34:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   34 |         freopen("tests.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
friends.cpp:35:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   35 |         freopen("tests.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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