Submission #702266

#	Time	Username	Problem	Language	Result	Execution time	Memory
702266		Koful123	JJOOII 2 (JOI20_ho_t2)	C++17	1 / 100	1 ms	1236 KiB

ho_t2

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define endl "\n"
#define pb push_back
#define ff first
#define ss second
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
 
void solve(){
 
	int n,k;
	cin >> n >> k;
 
	int ans = 1e18; string s; cin >> s;
	vector<array<int,26>> cnt(n + 37);
	cnt[0][s[0] - 'A'] = 1;
	for(int i = 1; i < n; i++){
		for(int j = 0; j < 26; j++){
			cnt[i][j] = cnt[i-1][j];
		}
		cnt[i][s[i] - 'A']++;
	}
 
	auto check = [&](int i,int m,int ch){
		return (cnt[i][ch] - (m > 0 ? cnt[m-1][ch] : 0) >= k);
	};	
 
	for(int i = 0; i < n; i++){
		if(s[i] != 'I') continue;
		int l = 0,r = i;
		while(l < r){
			int m = (l + r + 1) / 2;
			if(check(i,m,'I'-'A')) l = m;
			else r = m - 1;
		}
		if(!check(i,l,'I'-'A')) continue;
		int pre = l - 1; r = l - 1; l = 0;
		while(l < r){
			int m = (l + r + 1) / 2;
			if(check(pre,m,'O'-'A')) l = m;
			else r = m - 1;	
		}
		if(!check(pre,l,'O'-'A')) continue;
		pre = l - 1; r = l - 1; l = 0;
		while(l < r){
			int m = (l + r + 1) / 2;
			if(check(pre,m,'J'-'A')) l = m;
			else r = m - 1;	
		}
		if(!check(pre,l,'J'-'A')) continue;
		ans = min(ans,i-l+1 - k*3);
	}
 
	cout << (ans == 1e18 ? -1 : ans) << endl;
}
 
signed main(){ 
 
	ios::sync_with_stdio(0);
	cin.tie(0);
 
	int t = 1;
//	cin >> t;
 
	while(t--)
		solve();
 	
	return 0;
}

• Subtask 1: 1 / 1
• Subtask 2: 0 / 12
• Subtask 3: 0 / 87