Submission #770706

#	Time	Username	Problem	Language	Result	Execution time	Memory
770706		JellyTheOctopus	JJOOII 2 (JOI20_ho_t2)	C++17	100 / 100	7 ms	3868 KiB

ho_t2

#include <bits/stdc++.h>
using namespace std;

#define f first
#define s second

int N, K;
string str;

int main() {
    cin >> N >> K >> str;
    vector<int> J, O, I;
    for (int i = 0; i < (int)str.size(); i++) {
        if (str[i] == 'J') {
            J.push_back(i+1);
        }
        else if (str[i] == 'O') {
            O.push_back(i+1);
        }
        else {
            I.push_back(i+1);
        }
    }
    vector<pair<int, int>> A, B, C;
    for (int i = 0; i+K-1 < (int)J.size(); i++) {
        A.emplace_back(J[i], J[K+i-1]);
    }
    for (int i = 0; i+K-1 < (int)O.size(); i++) {
        B.emplace_back(O[i], O[K+i-1]);
    }
    for (int i = 0; i+K-1 < (int)I.size(); i++) {
        C.emplace_back(I[i], I[K+i-1]);
    }
    int a = 0;
    int b = 0;
    int c = 0;
    int ans = INT_MAX;
    while (a < (int)A.size() && b < (int)B.size() && c < (int)C.size()) {
        if (B[b].f < A[a].s) {
            b++;
            continue;
        }
        if (C[c].f < B[b].s) {
            c++;
            continue;
        }
        ans = min(ans, C[c].s-A[a].f-3*K+1);
        a++;
    }
    if (ans == INT_MAX) ans = -1;
    cout << ans << "\n";
}


// Binary Search Sol (TLE)
/*int main() {
    cin >> N >> K >> s;
    vector<int> J, O, I;
    for (int i = 0; i < (int)s.size(); i++) {
        if (s[i] == 'J') J.push_back(i+1);
        else if (s[i] == 'O') O.push_back(i+1);
        else I.push_back(i+1);
    }
    O.push_back(INT_MAX);
    I.push_back(INT_MAX);
    int ans = INT_MAX;
    for (int i = 0; i+K-1 < (int)J.size(); i++) {
        int cur = 0;
        vector<int> arr;
        for (int j = i; j < i+K; j++) {
            if (!arr.empty()) cur += J[j]-arr.back()-1;
            arr.push_back(J[j]);
        }
        int u = upper_bound(O.begin(), O.end(), arr.back())-O.begin();
        if (u == INT_MAX) break;
        bool flag = false;
        for (int j = u; j < u+K; j++) {
            if (O[j] == INT_MAX) {
                flag = true;
                break;
            }
            cur += O[j]-arr.back()-1;
            arr.push_back(O[j]);
        }
        if (flag) break;
        u = upper_bound(I.begin(), I.end(), arr.back())-I.begin();
        if (u == INT_MAX) break;
        for (int j = u; j < u+K; j++) {
            if (I[j] == INT_MAX) {
                flag = true;
                break;
            }
            cur += I[j]-arr.back()-1;
            arr.push_back(I[j]);
        }
        if (flag) break;
        ans = min(ans, cur);
    }
    if (ans == INT_MAX) ans = -1;
    cout << ans << "\n";
}*/

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