Submission #728781

#	Time	Username	Problem	Language	Result	Execution time	Memory
728781		rominanafu	Three Friends (BOI14_friends)	C++11	0 / 100	50 ms	7140 KiB

friends

#include <bits/stdc++.h>

using namespace std;

int n, len;
string s;
string r1, r2;
bool unico = true;

bool caso1() {
    int ini = 0, fin = len+1;
    bool x = false;
    int cont=0;
    while (cont < len) {
        if (s[ini] != s[fin]) {
            ini++;
            x = true;
        }
        if (x && s[ini] != s[fin])
            return false;
        ini++;
        fin++;
        cont++;
    }
    return true;
}

bool caso2() {
    int ini = 0, fin = len;
    bool x = false;
    int cont=0;
    while (cont < len) {
        if (s[ini] != s[fin]) {
            fin++;
            x = true;
        }
        if (x && s[ini] != s[fin])
            return false;
        ini++;
        fin++;
        cont++;
    }
    return true;
}

int main() {
    ios_base::sync_with_stdio();
    cin.tie();
    cin >> n >> s;
    len = n/2;
    string r1 = "", r2 = "";
    if (caso1())
        r1 = s.substr(len+1, len);
    if (caso2())
        r2 = s.substr(0, len);
    if ((r1.length() != len && r2.length() != len) || (n&1) == 0)
        cout << "NOT POSSIBLE";
    else if (r1.length() != len)
        cout << r2;
    else if (r2.length() != len)
        cout << r1;
    else if (r1 != r2)
        cout << "NOT UNIQUE";
    else
        cout << r1;
    return 0;
}

Compilation message (stderr)

friends.cpp: In function 'int main()':
friends.cpp:56:22: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   56 |     if ((r1.length() != len && r2.length() != len) || (n&1) == 0)
      |          ~~~~~~~~~~~~^~~~~~
friends.cpp:56:44: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   56 |     if ((r1.length() != len && r2.length() != len) || (n&1) == 0)
      |                                ~~~~~~~~~~~~^~~~~~
friends.cpp:58:26: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   58 |     else if (r1.length() != len)
      |              ~~~~~~~~~~~~^~~~~~
friends.cpp:60:26: warning: comparison of integer expressions of different signedness: 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   60 |     else if (r2.length() != len)
      |              ~~~~~~~~~~~~^~~~~~

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