제출 #383293

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
383293		ritul_kr_singh	JJOOII 2 (JOI20_ho_t2)	C++17	100 / 100	9 ms	5624 KiB

ho_t2

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define sp << " " <<
#define nl << "\n"

int dp[2][1<<18], pos[3][1<<18];
int n, k;
string s;

void calc(int x, char C){
	int cnt = 0;
	pos[x][0] = -1;

	for(int i=0; i+1<n; ++i){
		if(s[i]==C) pos[x][++cnt] = i;
		if(cnt>=k) dp[x][i] = i-pos[x][cnt-k+1]+1-k;
		else dp[x][i] = n+n;
	}
}

signed main(){
	cin.tie(0)->sync_with_stdio(0);
	cin >> n >> k >> s;
	calc(0, 'J');
	reverse(s.begin(), s.end());
	calc(1, 'I');

	int ans = n+n, cnt = 0;
	for(int i=0; i<n; ++i){
		if(s[i]=='O') pos[2][++cnt] = i;
		if(cnt>=k){
			int a = pos[2][cnt-k+1] ? dp[1][pos[2][cnt-k+1]-1] : n+n;
			int b = i+1<n ? dp[0][n-2-i] : n+n;
			ans = min(ans, a + b + i-pos[2][cnt-k+1]+1-k);
		}
	}
	if(ans>=n) ans = -1;
	cout << ans;
}

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