Submission #1112220

#	Time	Username	Problem	Language	Result	Execution time	Memory
1112220		lucascgar	Three Friends (BOI14_friends)	C++17	35 / 100	1072 ms	6412 KiB

friends

#include <bits/stdc++.h>

using namespace std;

/*

*/

typedef pair<int, int> pii;
typedef pair<long long, long long> pll;
typedef pair<long double, long double> pdd;

const int MAXN = 2e6+11;

int q[27];  // A = 0

signed main(){
    std::ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    cin >> n;
    string s;
    cin >> s;
    for (auto &x:s) q[x-'A']++;
    int qo = 0, tg;
    for (int i=0;i<26;i++) if (q[i]%2==1){
        qo++, tg=i;
    }

    if (s.size()%2 == 0 || qo>1){
        cout << "NOT POSSIBLE\n";
        return 0;
    }

    vector<int> fans;
    int sz = n/2;

    // meio
    for (int i=0;i<n;i++){
        if ((i>0 && s[i] == s[i-1]) || s[i]-'A' !=tg){
            continue;
        }
        string a, b;
        int j = 0;
        while (a.size()<sz){
            if (j!=i) a.push_back(s[j]);
            j++;
        }
        while (b.size()<sz){
            if (j!=i) b.push_back(s[j]);
            j++;
        }
        if (a==b) fans.push_back(i);
    }

    if (fans.empty()){
        cout << "NOT POSSIBLE\n";
    }else if (fans.size()>1){
        cout << "NOT UNIQUE\n";

        // for (auto &x:fans) cerr << x << '\n';
    }
    else{
        int x = fans.back(), q=0, j=0;
        while (q<sz){
            if (j!=x){
                cout << s[j];
                q++;
            }
            j++;
        }
        cout << '\n';
    }

    return 0;
}

Compilation message (stderr)

friends.cpp: In function 'int main()':
friends.cpp:46:24: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   46 |         while (a.size()<sz){
      |                ~~~~~~~~^~~
friends.cpp:50:24: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   50 |         while (b.size()<sz){
      |                ~~~~~~~~^~~
friends.cpp:41:37: warning: 'tg' may be used uninitialized in this function [-Wmaybe-uninitialized]
   41 |         if ((i>0 && s[i] == s[i-1]) || s[i]-'A' !=tg){
      |             ~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~

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