Submission #977818

#	Time	Username	Problem	Language	Result	Execution time	Memory
977818		UltraFalcon	JJOOII 2 (JOI20_ho_t2)	C++17	100 / 100	5 ms	1172 KiB

ho_t2

#ifndef DEBUG
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,avx,avx2,abm,mmx,fma,popcnt")
#endif

#include <bits/stdc++.h>
// #define int long long
using ll = long long;

using namespace std;

signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);

    int n, k;
    cin >> n >> k;

    string s; cin >> s;

    int lj = 0;
    while (lj < n && s[lj] != 'J') lj++;
    int rj = lj;
    int j_cnt = 1;
    int cur_cost = 0;
    while ((rj+1)<n && j_cnt<k) {
        rj++;
        j_cnt += s[rj] == 'J';
        // cur_cost += s[rj] != 'J';
    }
    int ro = rj;
    int o_cnt = 0;
    while ((ro+1)<n && o_cnt < k) {
        ro++;
        o_cnt += s[ro] == 'O';
        // cur_cost += s[ro] != 'O';
    }
    int ri = ro;
    int i_cnt = 0;
    while ((ri+1)<n && i_cnt<k) {
        ri++;
        i_cnt += s[ri] == 'I';
    }

    if (j_cnt<k || o_cnt<k || i_cnt<k) {
        cout << -1 << "\n";
        return 0;
    }

    cur_cost = (ri-lj+1) - 3*k;
    int res = cur_cost;
    while (ri < n) {
        rj++;
        while (rj < n && s[rj] != 'J') {
            // cur_cost += s[rj] != 'J';
            o_cnt -= (s[rj]=='O' && rj<=ro);
            i_cnt -= (s[rj]=='I' && rj > ro && rj<=ri);
            rj++;
        }
        lj++;
        while (lj<n && s[lj]!='J') {
            // cur_cost -= s[lj] != 'J';
            lj++;
        }

        ro = max(ro, rj);
        while ((ro+1)<n && o_cnt<k) {
            ro++;
            o_cnt += s[ro]=='O';
            i_cnt -= (s[ro]=='I' && ro<=ri);
        }

        ri = max(ri, ro);
        while ((ri+1)<n && i_cnt<k) {
            ri++;
            i_cnt += s[ri]=='I';
        }

        if (rj>=n || ro>=n || ri >= n) break;
        if (j_cnt<k || o_cnt<k || i_cnt<k) break;

        cur_cost = (ri-lj+1) - 3*k;
        res = min(res, cur_cost);
    }
    
    cout << res << "\n";

}

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