Submission #1131500

#	Time	Username	Problem	Language	Result	Execution time	Memory
1131500		kasdo	JJOOII 2 (JOI20_ho_t2)	C++20	0 / 100	0 ms	320 KiB

ho_t2

#include <bits/stdc++.h>
#include <vector>
#include <algorithm>

using namespace std;

int main() {
    int N, K;
    string S;
    cin >> N >> K >> S;

    // Store positions of J, O, and I
    vector<int> J_pos, O_pos, I_pos;
    for (int i = 0; i < N; i++) {
        if (S[i] == 'J') J_pos.push_back(i);
        else if (S[i] == 'O') O_pos.push_back(i);
        else if (S[i] == 'I') I_pos.push_back(i);
    }

    // Check if it's even possible to have K J's, K O's, and K I's
    if (J_pos.size() < K || O_pos.size() < K || I_pos.size() < K) {
        cout << -1 << endl;
        return 0;
    }

    // Minimize Operation 3 deletions
    int min_operations = INT_MAX;

    // Iterate over valid JOI segments
    for (int j = 0; j <= J_pos.size() - K; j++) {
        int start_J = J_pos[j];
        int end_J = J_pos[j + K - 1];

        auto it_O = lower_bound(O_pos.begin(), O_pos.end(), end_J);
        if (it_O == O_pos.end() || distance(it_O, O_pos.end()) < K) continue;

        int start_O = *it_O;
        int end_O = O_pos[it_O - O_pos.begin() + K - 1];

        auto it_I = lower_bound(I_pos.begin(), I_pos.end(), end_O);
        if (it_I == I_pos.end() || distance(it_I, I_pos.end()) < K) continue;

        int start_I = *it_I;
        int end_I = I_pos[it_I - I_pos.begin() + K - 1];

        // Calculate operations
        int operations = (start_J) + (N - 1 - end_I) +
                         (start_O - end_J - 1) +
                         (start_I - end_O - 1);

        min_operations = min(min_operations, operations);
    }

    // Output the result
    if (min_operations == INT_MAX) {
        cout << -1 << endl;
    } else {
        cout << min_operations << endl;
    }

    return 0;
}

• Subtask 1: 0 / 1
• Subtask 2: 0 / 12
• Subtask 3: 0 / 87