Submission #743313

#	Time	Username	Problem	Language	Result	Execution time	Memory
743313		irmuun	Three Friends (BOI14_friends)	C++17	100 / 100	13 ms	7324 KiB

friends

#include<bits/stdc++.h>
 
using namespace std;
 
#define pb push_back
#define ll long long
#define ff first
#define ss second
#define all(s) s.begin(),s.end()

bool check(string s,string t){
    int n=s.size();
    int cur=0;
    for(int i=0;i<s.size();i++){
        if(cur<n-1&&s[i]==t[cur]){
            cur++;
        }
    }
    return (cur==n-1);
}

int main(){
    ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
    int n;
    cin>>n;
    string s;
    cin>>s;
    if(n%2==0){
        cout<<"NOT POSSIBLE";
        return 0;
    }
    set<string>st;
    if(check(s.substr(n/2,n/2+1),s.substr(0,n/2))==true){
        st.insert(s.substr(0,n/2));
    }
    if(check(s.substr(0,n/2+1),s.substr(n/2+1,n/2))==true){
        st.insert(s.substr(n/2+1,n/2));
    }
    if(st.size()==0){
        cout<<"NOT POSSIBLE";
    }
    else if(st.size()==1){
        cout<<*st.begin();
    }
    else{
        cout<<"NOT UNIQUE";
    }
}

Compilation message (stderr)

friends.cpp: In function 'bool check(std::string, std::string)':
friends.cpp:14:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   14 |     for(int i=0;i<s.size();i++){
      |                 ~^~~~~~~~~

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