动态规划-最短编辑距离

package dynamic;

public class EditDistance {

    // 最短编辑距离,动态规划
    static int minDistance(String s1, String s2) {
        int m = s1.length(), n = s2.length();
        // dp[i][j] i,j表示字符个数
        int[][] dp = new int[m + 1][n + 1];
        for (int i = 0; i < m + 1; i++) {
            dp[i][0] = i;
        }
        for (int j = 1; j < n + 1; j++) {
            dp[0][j] = j;
        }
        for (int i = 1; i < m + 1; i++) {
            for (int j = 1; j < n + 1; j++) {
                if (s1.charAt(i - 1) == s2.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); // 插入,删除
                    dp[i][j] = Math.min(dp[i][j], dp[i - 1][j - 1] + 1); // 替换
                }
            }
        }
        return dp[m][n];
    }

    public static void main(String[] args) {
        int a = minDistance("", "");
    }

}