# Leetcode: Find and Replace Pattern

Find and Replace Pattern Similar Problems:

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

Github: code.dennyzhang.com

Credits To: leetcode.com

Leave me comments, if you have better ways to solve.

• Solution:
```// Blog link: https://code.dennyzhang.com/find-and-replace-pattern
// Basic Ideas: hashmap
// Complexity: Time O(n), Space O(1)
func encodeString(word string) string {
m := map[rune]int{}
i, s := 0, ""
for _, ch := range word {
_, ok := m[ch]
if !ok {
m[ch] = i
i++
}
s += string('a'+byte(m[ch]))
}
return s
}

func findAndReplacePattern(words []string, pattern string) []string {
p := encodeString(pattern)
res := []string{}
for _, word := range words {
if encodeString(word) == p {
res = append(res, word)
}
}
return res
}
```

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