583. Delete Operation for Two Strings

Problem:

Given two words word1 and word2, find the minimum number of steps required to make word1 and word2 the same, where in each step you can delete one character in either string.

Example 1:

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

Note:

1. The length of given words won't exceed 500.
2. Characters in given words can only be lower-case letters.

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Analysis:
几乎和 Minimum ASCII Delete Sum for Two Strings 一模一样。面试如果遇到这样明显的马甲肯定挣翻。

Solution:

class Solution {
    public int minDistance(String word1, String word2) {
        int m = word1.length();
        int n = word2.length();
        int[][] dp = new int[m + 1][n + 1];
        char[] c1 = word1.toCharArray();
        char[] c2 = word2.toCharArray();

        for (int j = 1; j <= n; j++) {
            dp[0][j] = dp[0][j - 1] + 1;
        }

        for (int i = 1; i <= m; i++) {
            dp[i][0] = dp[i - 1][0] + 1;
            for (int j = 1; j <= n; j++) {
                if (c1[i - 1] == c2[j - 1]) {
                    dp[i][j] = dp[i - 1][j - 1]; 
                } else {
                    dp[i][j] = Math.min(dp[i - 1][j], dp[i][j - 1]) + 1;
                }
            }
        }

        return dp[m][n];

    }
}