leetcode 72. Edit Distance

leetcode 72. Edit Distance

编辑距离，动态规划

public class Solution {
    public int minDistance(String word1, String word2) {
        int l_1 = word1.length();
        int l_2 = word2.length();
        // if(l_1==0)  return l_2;
        // if(l_2==0)  return l_1;
        int[][] dp = new int[l_1+1][l_2+1];
        for(int i=1;i<=l_1;i++){
            dp[i][0]=i;
        }
        for(int j=1;j<=l_2;j++){
            dp[0][j]=j;
        }
        for(int i=1;i<=l_1;i++){
            for(int j=1;j<=l_2;j++){
                //replace
                if(word1.charAt(i-1)==word2.charAt(j-1)){
                    dp[i][j] = dp[i-1][j-1];
                }else{
                    dp[i][j] = dp[i-1][j-1] + 1;
                }
                //insert
                dp[i][j] = dp[i][j]<(dp[i][j-1]+1)?dp[i][j]:(dp[i][j-1]+1);
                //delete
                dp[i][j] =  dp[i][j]<(dp[i-1][j]+1)?dp[i][j]:(dp[i-1][j]+1);                 
            }
        }
        return dp[l_1][l_2];
    }
}