Leetcode Problem 1181. Before and After Puzzle

1181. Before and After Puzzle

Leetcode Solutions

Using HashMaps and Sets for Efficient Matching

  1. Initialize two hash maps: first to map the first word to the remaining phrase, and last to map the last word to the remaining phrase.
  2. Initialize a set res to store the distinct results.
  3. Iterate over each phrase in the input list: a. Find the first and last words of the phrase. b. For each phrase in the first map that matches the last word of the current phrase, add the combined phrase to res. c. For each phrase in the last map that matches the first word of the current phrase, add the combined phrase to res. d. Insert the remaining phrase into the first and last maps with the corresponding first and last words as keys.
  4. Convert the set res to a list, sort it, and return.
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Brute Force Approach with String Comparisons

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