890. Find and Replace Pattern

You have a list of `words` and a `pattern`, and you want to know which words in `words` matches the pattern.

A word matches the pattern if there exists a permutation of letters `p` so that after replacing every letter `x` in the pattern with `p(x)`, we get the desired word.

(Recall that a permutation of letters is a bijection from letters to letters: every letter maps to another letter, and no two letters map to the same letter.)

Return a list of the words in `words` that match the given pattern.

You may return the answer in any order.

Example 1:

```Input: words = ["abc","deq","mee","aqq","dkd","ccc"], pattern = "abb"
Output: ["mee","aqq"]
Explanation: "mee" matches the pattern because there is a permutation {a -> m, b -> e, ...}.
"ccc" does not match the pattern because {a -> c, b -> c, ...} is not a permutation,
since a and b map to the same letter.```

Note:

• `1 <= words.length <= 50`
• `1 <= pattern.length = words[i].length <= 20`

890. Find and Replace Pattern
``````struct Solution;
use std::collections::HashMap;

trait Matches {
fn matches(&self, pattern: &[char], n: usize) -> bool;
}

impl Matches for Vec<char> {
fn matches(&self, pattern: &[char], n: usize) -> bool {
if self.len() != n {
return false;
}
let mut hm1: HashMap<char, char> = HashMap::new();
let mut hm2: HashMap<char, char> = HashMap::new();
for i in 0..n {
let c1 = self[i];
let c2 = pattern[i];
if let Some(old) = hm1.insert(c1, c2) {
if old != c2 {
return false;
}
}
if let Some(old) = hm2.insert(c2, c1) {
if old != c1 {
return false;
}
}
}
true
}
}

impl Solution {
fn find_and_replace_pattern(words: Vec<String>, pattern: String) -> Vec<String> {
let n = pattern.len();
let pattern: Vec<char> = pattern.chars().collect();
let mut res = vec![];
for word in words {
let word: Vec<char> = word.chars().collect();
if word.matches(&pattern, n) {
res.push(word.iter().collect());
}
}
res
}
}

#[test]
fn test() {
let words = vec_string!["abc", "deq", "mee", "aqq", "dkd", "ccc"];
let pattern = "abb".to_string();
let res = vec_string!["mee", "aqq"];
assert_eq!(Solution::find_and_replace_pattern(words, pattern), res);
}
``````