Submission #1102081

#	Time	Username	Problem	Language	Result	Execution time	Memory
1102081		stdfloat	JJOOII 2 (JOI20_ho_t2)	C++17	100 / 100	13 ms	2172 KiB

ho_t2

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

using ll = long long;

#define sz(v)	(int)(v).size()
#define all(v)	(v).begin(), (v).end()

int f(char c) {
	return (c == 'J' ? 0 : 1 + (c == 'I'));
}

int main() {
	ios::sync_with_stdio(false); cin.tie(nullptr);

	int n, k;
	string s;
	cin >> n >> k >> s;

	vector<int> v[3];
	for (int i = 0; i < n; i++)
		v[f(s[i])].push_back(i);

	int mn = n;
	for (int i = 0; i < n; i++) {
		if (s[i] != 'J') continue;
	
		int x = i - 1;
		for (int j = 0; j < 3; j++) {
			x = upper_bound(all(v[j]), x) - v[j].begin();

			if (x + k > sz(v[j])) {
				x = n; break;
			}

			x = v[j][x + k - 1];
		}

		if (x == n) break;

		mn = min(mn, x - i);
	}

	cout << (mn == n ? -1 : mn + 1 - 3 * k);
}

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