刷题训练 day48 | 第九章 动态规划 part16

题目1：

class Solution {
    public int minDistance(String word1, String word2) {
        int[][] dp =new int[word1.length()+1][word2.length()+1];
        for (int i=0;i<dp.length;i++){
            dp[i][0]=i;
        }
        for (int j=0;j<dp[0].length;j++){
            dp[0][j]=j;
        }
        for (int i=1;i<dp.length;i++){
            for (int j=1;j<dp[0].length;j++){
                if (word1.charAt(i-1)==word2.charAt(j-1)){
                    dp[i][j]=dp[i-1][j-1];
                }else{
                    dp[i][j] = Math.min (dp[i-1][j]+1,dp[i][j-1]+1);
                }
            }
        }
        return dp[word1.length()][word2.length()];
    }
}

题目2：

class Solution {
    public int minDistance(String word1, String word2) {
        int[][] dp = new int[word1.length()+1][word2.length()+1];
        for (int i=0;i<dp.length;i++){
            dp[i][0]=i;
        }
        for (int j=0;j<dp[0].length;j++){
            dp[0][j]=j;
        }
        for (int i=1;i<dp.length;i++){
            for (int j=1;j<dp[0].length;j++){
                if (word1.charAt(i-1)==word2.charAt(j-1)){
                dp[i][j]=dp[i-1][j-1];
                }else{
                dp[i][j]=Math.min(dp[i-1][j]+1,Math.min(dp[i][j-1]+1,dp[i-1][j-1]+1));
                //对第二个字符串删除相当于对第一个字符串增加
                }
            }
        }
        return dp[word1.length()][word2.length()];
    }
}