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 characterb) Delete a characterc) Replace…

题目描写叙述: 给定一个源串和目标串.可以对源串进行例如以下操作:  1. 在给定位置上插入一个字符  2. 替换随意字符  3. 删除随意字符 写一个程序.返回最小操作数,使得对源串进行这些操作后等于目标串,源串和目标串的长度都小于2000. 思路: 设状态dp[i][j] 表示从源串s[0...i] 和 目标串t[0...j] 的最短编辑距离 边界为:dp[i][0] = i,dp[0][j] = j 递推方程: 假设s[i] == t[j], 那么 dp[i][j] = dp[i-1][j…

http://blog.csdn.net/abcjennifer/article/details/7735272 自然语言处理(NLP)中,有一个基本问题就是求两个字符串的minimal Edit Distance, 也称Levenshtein distance.受到一篇Edit Distance介绍文章的启发,本文用动态规划求取了两个字符串之间的minimal Edit Distance. 动态规划方程将在下文进行讲解. 简单地说,就是仅通过插入(insert).删除(delete)和替换(s…

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 char…

引言 二维动态规划中最常见的是棋盘型二维动态规划. 即 func(i, j) 往往只和 func(i-1, j-1), func(i-1, j) 以及 func(i, j-1) 有关 这种情况下,时间复杂度 O(n*n),空间复杂度往往可以优化为O(n) 例题  1 Minimum Path Sum  Given a m x n grid filled with non-negative numbers, find a path from top left to bottom right whi…

Leetcode之动态规划(DP)专题-72. 编辑距离(Edit Distance) 给定两个单词 word1 和 word2,计算出将 word1 转换成 word2 所使用的最少操作数 . 你可以对一个单词进行如下三种操作: 插入一个字符 删除一个字符 替换一个字符 示例 1: 输入: word1 = "horse", word2 = "ros" 输出: 3 解释: horse -> rorse (将 'h' 替换为 'r') rorse -> r…

题目描述Edit DistanceGiven 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) Del…

Given two strings S and T, determine if they are both one edit distance apart. 这道题是之前那道Edit Distance的拓展,然而这道题并没有那道题难,这道题只让我们判断两个字符串的编辑距离是否为1,那么我们只需分下列三种情况来考虑就行了: 1. 两个字符串的长度之差大于1,那么直接返回False 2. 两个字符串的长度之差等于1,那么长的那个字符串去掉一个字符,剩下的应该和短的字符串相同 3. 两个字符串的长度之…

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 characterb) Delete a characterc) Replace…

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 characterb) Delete a chara…