Algorithm

C. Watto and Mechanism
time limit per test
3 seconds
memory limit per test
256 megabytes
problem link- https://codeforces.com/problemset/problem/514/C
input
standard input
output
standard output

Watto, the owner of a spare parts store, has recently got an order for the mechanism that can process strings in a certain way. Initially the memory of the mechanism is filled with n strings. Then the mechanism should be able to process queries of the following type: "Given string s, determine if the memory of the mechanism contains string t that consists of the same number of characters as s and differs from s in exactly one position".

Watto has already compiled the mechanism, all that's left is to write a program for it and check it on the data consisting of n initial lines and m queries. He decided to entrust this job to you.

Input

The first line contains two non-negative numbers n and m (0 ≤ n ≤ 3·105, 0 ≤ m ≤ 3·105) — the number of the initial strings and the number of queries, respectively.

Next follow n non-empty strings that are uploaded to the memory of the mechanism.

Next follow m non-empty strings that are the queries to the mechanism.

The total length of lines in the input doesn't exceed 6·105. Each line consists only of letters 'a', 'b', 'c'.

Output

For each query print on a single line "YES" (without the quotes), if the memory of the mechanism contains the required string, otherwise print "NO" (without the quotes).

Examples
input
Copy
2 3
aaaaa
acacaca
aabaa
ccacacc
caaac
output
Copy
YES
NO
NO



 

Code Examples

#1 Code Example with C++ Programming

Code - C++ Programming

#include <iostream>
#include <string>
#include <algorithm>

using namespace std;

struct trie {
	bool is_end;
	trie* next[3];

	trie() {
		is_end = false;
		for(int i = 0; i < 3; i++)
			next[i] = NULL;
	}
};

trie* root;
string in, s;

void insert(string s) {
	trie* cursor = root;

	for(int i = 0, len = s.length(); i < len; i++) {
		int number = s[i] - 'a';

		if(cursor->next[number] == NULL) {
			cursor->next[number] = new trie;
			cursor->next[number]->is_end = false;
			for(int j = 0; j < 3; j++)
				cursor->next[number]->next[j] = NULL;
		}

		cursor = cursor->next[number];
	}

	cursor->is_end = true;
}

int find(trie* tmp, int cur, int diff) {
	int res = 0;
	
	if(diff > 1 || cur > s.length())
		return false;

	if(cur == s.length())
		return diff && tmp->is_end;
		
	int number = s[cur] - 'a';

	if(tmp->next[0] != NULL) {
		res = max(res, find(tmp->next[0], cur+1, diff + (number != 0)));
	}

	if(tmp->next[1] != NULL) {
		res = max(res, find(tmp->next[1], cur+1, diff + (number != 1)));
	}

	if(tmp->next[2] != NULL) {
		res = max(res, find(tmp->next[2], cur+1, diff + (number != 2)));
	}

	return res;
}

void freeTrie(trie* cursor) {
	if(cursor == NULL)
		return;

	for(int i = 0; i < 3; i++)
		freeTrie(cursor->next[i]);

	delete[] cursor;
}

int main() {
	root = new trie;

	int n, m;
	cin >> n >> m;

	for(int i = 0; i < n; i++) {
		cin >> in;
		insert(in);
	}

	for(int i = 0; i < m; i++) {
		cin >> s;
		
		if(find(root, 0, 0))
			cout << "YES" << endl;
		else
			cout << "NO" << endl;
	}

	freeTrie(root);

	return 0;
}
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Input

x
–
+
cmd
2 3
aaaaa
acacaca
aabaa
ccacacc
caaac

Output

x
–
+
cmd
YES
NO
NO
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Demonstration

Codeforces Solution-Watto and Mechanism-Solution in C, C++, Java, Python

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