Submission #398943

#	Time	Username	Problem	Language	Result	Execution time	Memory
398943		katwamiaw	Three Friends (BOI14_friends)	C++14	100 / 100	73 ms	14932 KiB

friends

#include<bits/stdc++.h>
using namespace std ;

//it ain't much but it's honest work

int n ;
set<string>r ;
string ans , s ;
void ihope( string a , string b){
    string c ;
    //cout << a << ' ' << b << endl ;
    int ac=0 , bc=0 ;
    for(int i=0 ; i<n/2 ; i++){
        if(a[i]!=b[bc]){
            bc++ ;
        }
        if(a[i]==b[bc]){
            c+=a[i] ;
        }
        bc++ ;
        if(bc>n/2) break ;
    }
    //cout << c << endl ;
    if(c.size()==n/2){
        ans=c ;
        r.insert(ans) ;
    }
}

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL), cout.tie(NULL);
    cin >> n >> s ;
    if(n%2==0){
        cout << "NOT POSSIBLE" ;
        return 0 ;
    }
    string a1 , b1 ;
    for(int i=0 ; i<n/2 ; i++){
        a1+=s[i] ;
    }
    for(int i=n/2 ; i<n ; i++){
        b1+=s[i] ;
    }
    ihope(a1 , b1) ;
    string a2 , b2 ;
    for(int i=0 ; i<n/2+1 ; i++){
        a2+=s[i] ;
    }
    for(int i=n/2+1 ; i<n ; i++){
        b2+=s[i] ;
    }
    ihope(b2 , a2) ;
    string a3 , b3 ;
    for(int i=0 ; i<n/2 ; i++){
        a3+=s[i] ;
    }
    for(int i=n/2+1 ; i<n ; i++){
        b3+=s[i] ;
    }
    ihope(a3,b3) ;
    if(r.size()>1){
        cout << "NOT UNIQUE" ;
    }
    else if(r.size()==0){
        cout << "NOT POSSIBLE" ;
    }
    else{
        cout << ans ;
    }
}

Compilation message (stderr)

friends.cpp: In function 'void ihope(std::string, std::string)':
friends.cpp:24:16: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   24 |     if(c.size()==n/2){
      |        ~~~~~~~~^~~~~
friends.cpp:12:9: warning: unused variable 'ac' [-Wunused-variable]
   12 |     int ac=0 , bc=0 ;
      |         ^~

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