Submission #256941

#	Time	Username	Problem	Language	Result	Execution time	Memory
256941		akat	JJOOII 2 (JOI20_ho_t2)	C++14	100 / 100	10 ms	1548 KiB

ho_t2

#include<bits/stdc++.h>
using namespace std;
string s;
int k;
deque<int> d[3];
char c[3] = {'J', 'O', 'I'};
int last[3];
void rem(int x)
{
	while((int)d[x].size() > k)
		d[x].pop_front();
}
void update(int x, int y)
{
	rem(x);
	for(int l = last[y] + 1; l < d[x].front(); l++)
		if(s[l] == c[y]) d[y].push_back(l);
	last[y] = d[x].front() - 1;
}
void add_letter(int x)
{
	int l;
	for(l = 0; l < 2; l++)
	{
		if((int)d[l].size() < k)
		{
			if(s[x] == c[l])
			{
				d[l].push_back(x);
				last[l] = x;
			}
			if(d[l].size() == 1)
			{
				while(l)
				{
					update(l,l-1);
					l--;
				}
				rem(0);
			}
			return;
		}
	}
	if(s[x] != c[2]) return;
	d[2].push_back(x);
	last[2] = x;
	update(2,1);
	update(1,0);
	rem(0);
}
int main()
{
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	int n, l, ans = -1;
	cin>>n>>k>>s;
	for(l = 0; l < n; l++)
	{
		add_letter(l);
		if((int)d[2].size() == k)
		{
			int cans = d[2].back() - d[0].front() + 1 - k * 3;
			if(ans == -1 || ans > cans) ans = cans;
		}
	}
	cout<<ans<<'\n';
}

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