Submission #968741

#	Time	Username	Problem	Language	Result	Execution time	Memory
968741		youssef_3breheem	Three Friends (BOI14_friends)	C++14	0 / 100	47 ms	4352 KiB

friends

#include <bits/stdc++.h>
//#pragma GCC optimize("O3,unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
 
using namespace __gnu_pbds;
using namespace std;
 
typedef long long i64;
#define speed_up ios::sync_with_stdio(false);cin.tie(nullptr);
#define ordered_set(datatype) tree<datatype,null_type,less<datatype>,rb_tree_tag,tree_order_statistics_node_update>
template<class T> using ordered_multiset = tree<T, null_type, less_equal<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define all(V) V.begin(), V.end()
#define rall(V) V.rbegin(), V.rend()
#define isON(N,K) (N&(1<<K))
#define endl '\n'
 
const int N = 2e3 + 7;
const int MOD = 1e9 + 7;
const double PI = 3.14159265358979323846;
long double EPS = 1e-9;
const int NOT_VISITED=0,IN_PROGRESS=1,VISITED=3;
const int dr[]={-1,0,1,0};
const int dc[]={0,1,0,-1};
 
template<class T>
istream &operator>>(istream &in, vector<T> &v) {
    for (auto &it : v) in >> it;
    return in;
}
 
template<class T>
ostream &operator<<(ostream &out, vector<T> &v) {
    for (auto &it : v) out << it << ' ';
    return out;
}
 
vector<i64> get_div(i64 n){
    vector<i64>v;
    for (i64 i = 1; i*i <= n; ++i) {
        if(n%i==0){
            if(n/i==i)v.push_back(i);
            else{v.push_back(i);v.push_back(n/i);}
        }
    }
    return v;
}
 
void TC(){
    int n;
    cin >> n;
    string s,ans;
    cin >> s;
    map<int,int>mp;
    for(auto &i:s)mp[i]++;
    bool f=false;
    for(auto &i:mp){
        if(i.second==2)ans.push_back(i.first);
        else if(i.second>2)f=true;
    }
    if(ans.size()==n/2)cout << ans;
    else if(f)cout << "NOT UNIQUE";
    else cout << "NOT POSSIBLE";
}
 
signed main() {
    speed_up
    int tt = 1;
//    cin >> tt;
    while(tt--) {
        TC();
        cout << endl;
    }
}

Compilation message (stderr)

friends.cpp: In function 'void TC()':
friends.cpp:62:18: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   62 |     if(ans.size()==n/2)cout << ans;
      |        ~~~~~~~~~~^~~~~

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