Codeforces Round #291 (Div. 2) --- C. Watto and mechanic,

Codeforces Round #291 (Div. 2) --- C. Watto and mechanic,

Watto, the owner of a spare parts store, has recently got an order for the mechanic that can process strings in a certain way. initially the memory of the mechanic is filled with n strings. then the mechanic shocould be able to process queries of the following type: "Given string s, determine if the memory of the mechanic 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 mechanic, 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 records ≤ limit n records ≤ limit 3 · 105, 0 records ≤ limit m records ≤ limit 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 mechanic.

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

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 mechanic contains the required string, otherwise print "NO" (without the quotes ).
Sample test (s)
Input

2 3
Aaaaa
Acacaca
Aabaa
Ccacacc
Caaac

Output

YES
NO
NO

Trie + dfs

/*************************************** * *********************************> File Name: cf291-c.cpp> Author: ALex> Mail: zchao1995@gmail.com> Created Time: ******************************** **************************************** /# include <map> # include <set> # include <queue> # include <stack> # include <vector> # include <cmath> # include <cstdio> # include <cstdlib> # include <cstri Ng> # include <iostream> # include <algorithm> using namespace std; const double pi = acos (-1); const int inf = 0x3f3f3f; const double eps = 1e-15; typedef long LL; typedef pair <int, int> PLL; const int N = 7*100010; char str [N]; int has_len [N]; int len; struct TRIE {TRIE * next [3]; int cnt; TRIE () {cnt = 0; next [0] = next [1] = next [2] = NULL ;}} * root; void insert (char str []) {int len = strlen (str ); TRIE * p = root; for (int I = 0; I <len; ++ I) {if (p-> next [str [I]-'a'] = NULL) {p-> next [str [I]-'a'] = new TRIE ();} p = p-> next [str [I]-'a'];} p-> cnt = 1;} bool find (TRIE * p, int cur, bool has) {if (cur = len) {return has & p-> cnt ;} bool flag = 0; for (int I = 0; I <3; ++ I) {if (p-> next [I]! = NULL) {if (I = str [cur]-'A') {flag | = find (p-> next [I], cur + 1, has );} else {if (has) {continue;} flag | = find (p-> next [I], cur + 1, 1) ;}} return flag ;} void DELETE (TRIE * p) {for (int I = 0; I <3; ++ I) {if (p-> next [I]! = NULL) {DELETE (p-> next [I]) ;}} delete p ;}int main () {int n, m; while (~ Scanf ("% d", & n, & m) {memset (has_len, 0, sizeof (has_len); root = new TRIE (); for (int I = 0; I <n; ++ I) {scanf ("% s", str); len = strlen (str); has_len [len] = 1; insert (str) ;}while (m --) {scanf ("% s", str); len = strlen (str); if (! Has_len [len]) {printf ("NO \ n"); continue;} if (find (root, 0, 0) {printf ("YES \ n ");} else {printf ("NO \ n") ;}} DELETE (root) ;}return 0 ;}