/*编辑距离 滚动数组*/
public class Solution {
    public int minDistance(String word1, String word2) {
        int l1 = word1.length();
        int l2 = word2.length();

        int dp[][] = new int[l1+1][l2+1];
        for(int i=0;i<=l1;i++) {
            dp[i][0] = i;
        }
        
        for(int j=0;j<=l2;j++) {
            dp[0][j] = j;
        }
        
        for(int i=1;i<=l1;i++) {
            for(int j=1;j<=l2;j++){
                if (word1.charAt(i-1) == word2.charAt(j-1)){
                    dp[i][j] = dp[i-1][j-1];
                }else{
                    dp[i][j] = Math.min(Math.min(dp[i-1][j],dp[i][j-1]),dp[i-1][j-1]) + 1;
                }
            }
        }
        return dp[l1][l2];
    }
}