Alien Dictionary Order: Implementing Character Sorting with Topological Sort and Custom Comparisons #2044
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This project demonstrates how to determine the order of characters in an alien language using a given dictionary of words. The code solves the problem in two key parts:
Finding Character Order:
We first construct a graph where each node represents a character. Directed edges between nodes indicate which character should appear before another in the alien dictionary. This is based on the first differing character between adjacent words in the dictionary.
Using topological sorting via Depth-First Search (DFS), we determine the order of characters in this alien language.
Custom Sorting of Words:
With the character order determined, we sort the words in the dictionary using a custom comparison function. This function compares two words based on their characters' positions in the alien dictionary order.
To optimize the sorting process, an unordered_map is used to store the order of each character, allowing for efficient comparisons between words.
The implementation involves key techniques such as graph construction, DFS-based topological sorting, and custom sorting with lambda functions. This solution efficiently handles various edge cases, including words of different lengths and prefix-based comparisons, providing a complete solution to determining the correct alien dictionary order and verifying word sorting.