HardDp
Edit Distance
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Given two strings word1 and word2, return the minimum number of operations required to convert word1 to word2.
You have the following three operations permitted on a word:
- Insert a character
- Delete a character
- Replace a character
Examples
Example 1
Input
word1 = "horse", word2 = "ros"
Output
3
horse -> rorse (replace 'h' with 'r') -> rose (remove second 'r') -> ros (remove 'e'). Three operations total.
Example 2
Input
word1 = "intention", word2 = "execution"
Output
5
Five operations: remove 't', replace 'i' with 'e', replace first 'n' with 'x', replace second 'n' with 'c', insert 'u'.
Constraints
- 0 <= word1.length, word2.length <= 500
- word1 and word2 consist of lowercase English letters
Optimal complexity
Time
O(m * n)
Space
O(m * n)
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