Today I have done leetcode's July LeetCoding Challenge with cpp.

July LeetCoding Challenge 29

Description

Find and Replace Pattern

Given a list of strings words and a string pattern, return a list of words[i] that match pattern. You may return the answer in any order.

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.

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.

Example 2:

Input: words = ["a","b","c"], pattern = "a"
Output: ["a","b","c"]

Constraints:

• 1 <= pattern.length <= 20
• 1 <= words.length <= 50
• words[i].length == pattern.length
• pattern and words[i] are lowercase English letters.

Solution

string unify(string s) {
  char mp[26] = {};
  int cnt = 0;
  for(auto &c : s) {
    if(!mp[c - 'a']) {
      mp[c - 'a'] = 'a' + cnt;
      cnt += 1;
    }
    c = mp[c - 'a'];
  }
  return s;
}
class Solution {
public:
  vector<string> findAndReplacePattern(vector<string>& words, string pattern) {
    vector<string> answer;
    pattern = unify(pattern);
    for(auto &word : words) {
      if(unify(word) == pattern) answer.push_back(word);
    }
    return answer;
  }
};

// Accepted
// 47/47 cases passed (10 ms)
// Your runtime beats 28.33 % of cpp submissions
// Your memory usage beats 98.2 % of cpp submissions (7.7 MB)