Submission #564705

#	Time	Username	Problem	Language	Result	Execution time	Memory
564705		SSRS	Three Friends (BOI14_friends)	C++14	100 / 100	53 ms	7096 KiB

friends

#include <bits/stdc++.h>
using namespace std;
int main(){
  int N;
  cin >> N;
  string U;
  cin >> U;
  if (N % 2 == 0){
    cout << "NOT POSSIBLE" << endl;
  } else {
    int L1 = 0;
    while (L1 < (N - 1) / 2){
      if (U[L1] == U[L1 + (N + 1) / 2]){
        L1++;
      } else {
        break;
      }
    }
    int R1 = (N - 1) / 2;
    while (R1 >= 0){
      if (U[R1] == U[R1 + (N - 1) / 2]){
        R1--;
      } else {
        break;
      }
    }
    int L2 = (N - 1) / 2;
    while (L2 < N){
      if (U[L2] == U[L2 - (N - 1) / 2]){
        L2++;
      } else {
        break;
      }
    }
    int R2 = N - 1;
    while (R2 >= (N + 1) / 2){
      if (U[R2] == U[R2 - (N + 1) / 2]){
        R2--;
      } else {
        break;
      }
    }
    if (L1 >= R1 && L2 >= R2){
      if (U.substr(0, (N - 1) / 2) == U.substr((N + 1) / 2)){
        cout << U.substr(0, (N - 1) / 2) << endl;
      } else {
        cout << "NOT UNIQUE" << endl;
      }
    } else if (L1 >= R1){
      cout << U.substr((N + 1) / 2) << endl;
    } else if (L2 >= R2){
      cout << U.substr(0, (N - 1) / 2) << endl;
    } else {
      cout << "NOT POSSIBLE" << endl;
    }
  }
}

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