动态规划 两个字符串之间的编辑距离 leetcode72

     public static int minDistance(String word1, String word2) {
            char[] s1 = word1.toCharArray();
            char[] s2 = word2.toCharArray();
            int len1 = s1.length;
            int len2 = s2.length;
            int N = Math.max(len1, len2);
            int[][] d = new int[N + 1][N + 1];

            for (int i = 0; i <= N; i++) {
                d[i][0] = i;
                d[0][i] = i;
            }

            for (int i = 1; i <= len1; i++) {
                for (int j = 1; j <= len2; j++) {
                    if (s1[i - 1] == s2[j - 1]) {
                        d[i][j] = d[i - 1][j - 1];
                    } else {
                        d[i][j] = Math.min(d[i][j - 1] + 1, Math.min(d[i - 1][j] + 1, d[i - 1][j - 1] + 1));
                    }
                }
            }

             for (int i = 0; i <= N; i++) {// juzheng
             for (int j = 0; j <= N; j++) {
             System.out.print(d[i][j]+" ");
             }
             System.out.println();
             }

            return d[len1][len2];
        }