Submission #74686

#	Time	Username	Problem	Language	Result	Execution time	Memory
74686		kjain_1810	Three Friends (BOI14_friends)	C++17	100 / 100	99 ms	23376 KiB

friends

#include <iostream>
#include <string>

using namespace std;

string try_candidate(const string &s, int orig_start, int orig_len, int modified_start) {
    bool was_mismatch = false;
    int orig = orig_start, mod = modified_start, i = 0;
    while (i < orig_len) {
        if (s[orig] != s[mod]) {
            if (was_mismatch)
                return string();
            was_mismatch = true;
            mod++;
        } else
            orig++, mod++, i++;
    }
    return s.substr(orig_start, orig_len);
}

int main() {
    string final;
    int N;
    cin >> N;
    cin >> final;
    int orig_len = (final.length() - 1) / 2;
    const string&
        pos1 = try_candidate(final, orig_len + 1, orig_len, 0),
        pos2 = try_candidate(final, 0, orig_len, orig_len);
    if ( (pos1.empty() && pos2.empty()) || (final.size() % 2 == 0))
        cout << "NOT POSSIBLE" << endl;
    else if (pos1.empty())
        cout << pos2 << endl;
    else if (pos2.empty())
        cout << pos1 << endl;
    else if (pos1 != pos2)
        cout << "NOT UNIQUE" << endl;
    else 
        cout << pos1 << endl;
    return 0;
}

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