zoukankan      html  css  js  c++  java
  • Leetcode Edit Distance

    Given two words word1 and word2, find the minimum number of steps required to convert word1 to word2. (each operation is counted as 1 step.)

    You have the following 3 operations permitted on a word:

    a) Insert a character
    b) Delete a character
    c) Replace a character

    输入两个单词word1和word2,求出从word1转换成word2的最少步骤。每个转换操作算一步。转换操作限定于:

    • 删除一个字符
    • 插入一个字符
    • 替换一个字符

    本题用动态规划求解

    设决策变量dp[i][j],表示从word[0..i-1]转换为word2[0...j-1]的最少步骤

    可以参考http://web.stanford.edu/class/cs124/lec/med.pdf

    class Solution {
    public:
        int minDistance(string word1, string word2) {
            int len1 =word1.length(), len2 = word2.length();
            if(len1 == 0) return len2;
            if(len2 == 0) return len1;
            if(word1 == word2) return 0;
            vector<vector<int> > dp(len1+1, vector<int>(len2+1,0));
            for(int i = 0; i <= len1; ++ i) dp[i][0] = i;
            for(int j = 0; j <= len2; ++ j) dp[0][j] = j;
            for(int i =1; i <= len1; ++ i){
                for(int j = 1; j <= len2; ++ j){
                    dp[i][j] = min(dp[i-1][j-1]+(word1[i-1] != word2[j-1]? 1: 0),min(dp[i-1][j]+1, dp[i][j-1]+1));
                }
            }
            return dp[len1][len2];
        }
    };
  • 相关阅读:
    博客园代码
    前端
    1338. Reduce Array Size to The Half
    1220. Count Vowels Permutation
    363. Max Sum of Rectangle No Larger Than K
    366. Find Leaves of Binary Tree
    443. String Compression
    8 · Rotate String
    886. Possible Bipartition
    LT 183 wood cut
  • 原文地址:https://www.cnblogs.com/xiongqiangcs/p/3824701.html
Copyright © 2011-2022 走看看