Submission #1167997

#	Time	Username	Problem	Language	Result	Execution time	Memory
1167997		chikien2009	JJOOII 2 (JOI20_ho_t2)	C++20	100 / 100	4 ms	2888 KiB

ho_t2

#include <bits/stdc++.h>

using namespace std;

inline void setup()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

int n, k, res = 1e9, pre[200000], suf[200000];
string s;
vector<int> v, o;

int main()
{
    setup();

    cin >> n >> k >> s;
    for (int i = 0; i < n; ++i)
    {
        if (s[i] == 'O')
        {
            o.push_back(i);
        }
        else if (s[i] == 'J')
        {
            v.push_back(i);
        }
        pre[i] = (v.size() < k ? -1 : v[v.size() - k]);
    }
    v.clear();
    for (int i = n - 1; i >= 0; --i)
    {
        if (s[i] == 'I')
        {
            v.push_back(i);
        }
        suf[i] = (v.size() < k ? -1 : v[v.size() - k]);
    }
    for (int i = 0, x, y; i + k <= o.size(); ++i)
    {
        x = pre[o[i]];
        y = suf[o[i + k - 1]];
        if (x != -1 && y != -1)
        {
            res = min(res, y - x + 1 - 3 * k);
        }
    }
    cout << (res == 1e9 ? -1 : res);
    return 0;
}

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