Submission #201348

#	Time	Username	Problem	Language	Result	Execution time	Memory
201348		Mamnoon_Siam	JJOOII 2 (JOI20_ho_t2)	C++17	100 / 100	27 ms	5944 KiB

ho_t2

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

using ll = long long;
using ii = pair<int, int>;

const int maxn = 2e5 + 5;

int n, k;
int cnt[3][maxn];
int to[3][maxn];
int a[maxn];

int main(int argc, char const *argv[])
{
#ifdef LOCAL
	freopen("in", "r", stdin);
#endif
	cin >> n >> k;
	{
		string s; cin >> s;
		for(int i = 1; i <= n; i++) {
			if(s[i-1] == 'J') a[i] = 0;
			if(s[i-1] == 'O') a[i] = 1;
			if(s[i-1] == 'I') a[i] = 2;
		}
	}
	for(int i = 1; i <= n; i++) {
		cnt[a[i]][i]++;
		cnt[0][i] += cnt[0][i-1];
		cnt[1][i] += cnt[1][i-1];
		cnt[2][i] += cnt[2][i-1];
	}
	if(cnt[0][n] < k or cnt[1][n] < k or cnt[2][n] < k) {
		cout << "-1" << endl;
		return 0;
	}
	memset(to, -1, sizeof to);
	for(int x = 0; x < 3; x++) {
		int *cc = cnt[x];
		int r = 0;
		for(int i = 0; i < n; i++) {
			while(r < n and cc[r] - cc[i] < k) {
				r++;
			}
			if(cc[r] - cc[i] == k) {
				to[x][i] = r;
			}
		}
	}
	int ans = INT_MAX;
	for(int i = 0; i < n; i++) {
		int now = i, flag = 1;
		for(int x = 0; x < 3; x++) {
			if(to[x][now] == -1) {
				flag = 0;
				break;
			}
			now = to[x][now];
		}
		if(flag) {
			ans = min(ans, now - i);
		}
	}
	if(ans == INT_MAX) {
		cout << "-1" << endl;
	} else {
		cout << ans - 3*k << endl;
	}
	return 0;
}

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