Submission #924507

#	Time	Username	Problem	Language	Result	Execution time	Memory
924507		qwe1rt1yuiop1	JJOOII 2 (JOI20_ho_t2)	C++14	100 / 100	15 ms	2304 KiB

ho_t2

#include <bits/stdc++.h>
// #define int long long
using namespace std;
using pii = pair<int, int>;

void solve()
{
    int n, k;
    string s;
    cin >> n >> k >> s;

    vector<int> pj, po, pi;
    for (int i = 0; i < n; ++i)
    {
        if (s[i] == 'J')
            pj.emplace_back(i);
        else if (s[i] == 'O')
            po.emplace_back(i);
        else
            pi.emplace_back(i);
    }

    int ans = INT_MAX;
    for (int i = n; i >= 0; --i)
    {
        if (i != n)
        {
            if (s[i] == 'J')
                pj.pop_back();
            else if (s[i] == 'O')
                po.pop_back();
            else
                pi.pop_back();
        }

        if ((int)pi.size() < k)
            continue;
        int id = pi[(int)pi.size() - k];
        id = lower_bound(po.begin(), po.end(), id) - po.begin();
        if (id < k)
            continue;
        id -= k;
        id = lower_bound(pj.begin(), pj.end(), po[id]) - pj.begin();
        if (id < k)
            continue;
        id -= k;
        ans = min(ans, i - pj[id]);
    }

    if (ans == INT_MAX)
    {
        cout << "-1\n";
        return;
    }
    cout << ans - k * 3 << '\n';
}

/*
10 2
OJIJOIOIIJ

9 3
JJJOOOIII

9 1
IIIOOOJJJ
 */

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

    solve();

    return 0;
}

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