Submission #398825

#	Time	Username	Problem	Language	Result	Execution time	Memory
398825		YaserFaisal	Three Friends (BOI14_friends)	C++14	35 / 100	1069 ms	18076 KiB

friends

#include <bits/stdc++.h>
 
using namespace std ;
 
//#define int long long 
int MOD = 1e9+7 ;
int freq[200] ;
vector < int > v[200] ;

int32_t main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    int n ; cin >> n ; 
    string s ; cin >> s ; 
	for ( int i = 0 ; i < n ; i++ )
    {
        freq[s[i]]++ ;
        v[s[i]].push_back(i) ;
    }
    char c ;
    int odd = 0 ; 
    for ( int i = 'A' ; i <= 'Z' ; i++ )
    {
        if ( (freq[i] % 2) == 1 )
        {
            odd++ ;
            c = i ;
        }
    }
    if ( odd != 1 || (n % 2) == 0 )
    {
        cout << "NOT POSSIBLE" ;
        return 0 ;
    }
    string ans = "-" ;
    for ( int i = 0 ; i < v[c].size() ; i++ )
    {
        int x = v[c][i] ;
        string a , b ; 
        int m = n/2 ; 
        if ( x == m )
        {
            a = s.substr(0,m) ;
            b = s.substr(m+1) ;
        }
        if ( x < m )
        {
            a = s.substr(0,x) + s.substr(x+1,m-x) ;
            b = s.substr(m+1) ;
        }
        if ( x > m )
        {
            a = s.substr(0,m) ;
            b = s.substr(m,x-m) + s.substr(x+1) ;
        }
        //cout << x << " " << a << " " << b << " " << endl ;
        if ( a == b )
		{
			if ( a == ans ) continue ;
            else if ( ans == "-" ) ans = a ;
            else
            {
                cout << "NOT UNIQUE" << endl ;
                return 0 ;
            }
		}
    }
    if ( ans == "-" ) ans = "NOT POSSIBLE" ;
    cout << ans ;
}

Compilation message (stderr)

friends.cpp: In function 'int32_t main()':
friends.cpp:17:18: warning: array subscript has type 'char' [-Wchar-subscripts]
   17 |         freq[s[i]]++ ;
      |                  ^
friends.cpp:18:15: warning: array subscript has type 'char' [-Wchar-subscripts]
   18 |         v[s[i]].push_back(i) ;
      |               ^
friends.cpp:36:29: warning: array subscript has type 'char' [-Wchar-subscripts]
   36 |     for ( int i = 0 ; i < v[c].size() ; i++ )
      |                             ^
friends.cpp:36:25: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   36 |     for ( int i = 0 ; i < v[c].size() ; i++ )
      |                       ~~^~~~~~~~~~~~~
friends.cpp:38:19: warning: array subscript has type 'char' [-Wchar-subscripts]
   38 |         int x = v[c][i] ;
      |                   ^

• Subtask 1: 35 / 35
• Subtask 2: 0 / 65