Submission #922976

#	Time	Username	Problem	Language	Result	Execution time	Memory
922976		NintsiChkhaidze	JJOOII 2 (JOI20_ho_t2)	C++17	100 / 100	7 ms	6948 KiB

ho_t2

// Source: https://usaco.guide/general/io

#include <bits/stdc++.h>
#define pb push_back
using namespace std;
const int inf = 1e9;
vector <int> v[7];
int dp[200003][6];

int main() {
	ios_base::sync_with_stdio(0),cin.tie(NULL),cout.tie(NULL);
	int n,k;
	cin>>n>>k;

	string s;
	cin>>s;
	s='%'+s;

	map <char,int> mp;
	mp['J'] = 1;
	mp['O'] = 2;
	mp['I'] = 3;

	dp[0][1] = dp[0][2] = dp[0][3] = inf;
	int ans = inf;
 	for (int i = 1; i <= n; i++){
		v[mp[s[i]]].pb(i);

		for (int j = 1; j <= 3; j++){
			dp[i][j] = dp[i - 1][j] + 1;
			int t = v[j].size();
			if (t < k) continue;

			int l = v[j][t - k];
			int del = (i - l + 1 - k);
			dp[i][j] = min(dp[i][j],del + dp[l - 1][j - 1]);
		}

		ans=min(ans,dp[i][3]);
	}
	if (ans >= inf) ans=-1;
	cout<<ans<<endl;
}

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