Submission #42596

#	Time	Username	Problem	Language	Result	Execution time	Memory
42596		Hassoony	Three Friends (BOI14_friends)	C++14	0 / 100	79 ms	6668 KiB

friends

#include<bits/stdc++.h>
#include<unordered_map>
#define F first
#define S second
using namespace std;
typedef long long ll;
typedef long double D;
const ll inf=(1ll<<61);
const ll mod=1e9+7;
const int MX=309;
int n,fr[MX],sum;
string s;
int main(){
    cin>>n>>s;
    for(auto pp:s)fr[pp]++;
    for(int i='A';i<='Z';i++){
        if(fr[i]%2)sum++;
    }
    if(sum!=1){
        puts("NOT POSSIBLE");
        return 0;
    }
    sum=0;
    for(int i='A';i<='Z';i++){
        if(fr[i]%2){
            if(fr[i]!=1){
                puts("NOT UNIQUE");
                return 0;
            }
        }
    }
    int len=(n-1)/2;
    string ret="";
    for(auto pp:s){
        if(fr[pp]%2||ret.size()==len)continue;
        ret+=pp;
    }
    cout<<ret<<endl;
}

Compilation message (stderr)

friends.cpp: In function 'int main()':
friends.cpp:15:24: warning: array subscript has type 'char' [-Wchar-subscripts]
     for(auto pp:s)fr[pp]++;
                        ^
friends.cpp:35:17: warning: array subscript has type 'char' [-Wchar-subscripts]
         if(fr[pp]%2||ret.size()==len)continue;
                 ^
friends.cpp:35:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if(fr[pp]%2||ret.size()==len)continue;
                                ^

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