cf1149b dp

#include<bits/stdc++.h>
using namespace std;
 
typedef long long ll;
const int inf = 0x3f3f3f3f;
int n, q,ch[100010][26];
char s[100010], d[5][255];
int l[5], dp[255][255][255];
int main()
{
	ios::sync_with_stdio(false);
	cin.tie(0);
	cout.tie(0);
	cin >> n >> q;
	cin >> s;
	for (int i = 0; i < 26; i++) ch[n][i] = ch[n+1][i] = n + 1;
	for (int i = n - 1; i >= 0; i--)
	{
		int t = s[i] - 'a';
		for (int j = 0; j < 26; j++)
			ch[i][j] = ch[i + 1][j];
		ch[i][t] = i + 1;
	}
	memset(l, 0, sizeof(l));
	memset(dp,0,sizeof(dp)); 
	int x; char t;
	for (int p = 1; p <= q; p++)
	{
		cin >> t >> x;
		if (t == '-') l[x]--;
		else
		{
			l[x]++;
			cin >> t;
			d[x][l[x]] = t;
			int i = x == 1 ? l[x] : 0;
			for (; i <= l[1]; i++)
			{
				int j = x == 2 ? l[x] : 0;
				for (; j <= l[2]; j++)
				{
					int k = x == 3 ? l[x] : 0;
					for (; k <= l[3]; k++)
					{
						dp[i][j][k] = n + 1;
						if (i&&dp[i - 1][j][k]!=n+1)
							dp[i][j][k] = min(dp[i][j][k], ch[dp[i - 1][j][k]][d[1][i] - 'a']);
						if (j&&dp[i][j-1][k]!=n+1)
							dp[i][j][k] = min(dp[i][j][k], ch[dp[i][j - 1][k]][d[2][j] - 'a']);
						if (k&&dp[i][j][k-1]!=n+1)
							dp[i][j][k] = min(dp[i][j][k], ch[dp[i][j][k - 1]][d[3][k] - 'a']);
					}
				}
			}
		}
		if (dp[l[1]][l[2]][l[3]] <= n)
			cout << "YES" << endl;
		else
			cout << "NO" << endl;
	}
	return 0;
}