What is the approach to find the largest word by deleting characters?
Find the longest word in a dictionary that can be formed by deleting some characters from a given string. This tests string matching and greedy strategies.
Why Interviewers Ask This
This question evaluates your ability to design efficient string processing algorithms. It checks if you can implement a greedy approach to validate subsequence relationships quickly. Google interviewers want to see how you handle multiple queries against a dictionary and optimize for both time and readability.
How to Answer This Question
Describe iterating through each word in the dictionary and checking if it is a subsequence of the main string. Use two pointers to traverse both the dictionary word and the main string. Keep track of the longest valid word found so far. Discuss how to break ties if multiple words have the same maximum length, perhaps by lexicographical order.
Key Points to Cover
- Check subsequence property for each dictionary word
- Use two pointers for efficient matching
- Track the longest valid word found
- Handle tie-breaking conditions
Sample Answer
I would iterate through each word in the dictionary and check if it is a subsequence of the input string using a two-pointer approach. One pointer tracks the current character in the dictionary word, and the other scans…
Common Mistakes to Avoid
- Checking subsequences inefficiently leading to TLE
- Ignoring tie-breaking rules for equal-length words
- Not handling empty strings or null inputs
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