0583 - Delete Operation for Two Strings

0583 - Delete Operation for Two Strings

Given two strings word1 and word2, return the minimum number of steps required to make word1 and word2 the same.

In one step, you can delete exactly one character in either string.

Examples

Input: word1 = "sea", word2 = "eat" Output: 2 Explanation: You need one step to make "sea" to "ea" and another step to make "eat" to "ea".

Input: word1 = "leetcode", word2 = "etco" Output: 4

Constraints

• 1 <= word1.length, word2.length <= 500

• word1 and word2 consist of only lowercase English letters.

Java Solution (Dynammic Programming)

class Solution {
    public int minDistance(String s1, String s2) {
        int[][] dp = new int[s1.length() + 1][s2.length() + 1];
        for (int i = 0; i <= s1.length(); i++) {
            for (int j = 0; j <= s2.length(); j++) {
                if (i == 0 || j == 0)
                    continue;
                if (s1.charAt(i - 1) == s2.charAt(j - 1))
                    dp[i][j] = 1 + dp[i - 1][j - 1];
                else
                    dp[i][j] = Math.max(dp[i - 1][j], dp[i][j - 1]);
            }
        }
        return s1.length() + s2.length() - 2 * dp[s1.length()][s2.length()];
    }
}