Given 2 permutations of integers from 1 to N, you need to find the minimum number of operations necessary to change both or any one of them in such a way that they become exactly same. Here only two operations are allowed: either you can delete an in…

CJOJ 1070 [Uva]嵌套矩形(动态规划 图论) Description 有 n 个矩形,每个矩形可以用两个整数 a, b 描述,表示它的长和宽.矩形 X(a, b) 可以嵌套在矩形 Y(c, d) 中当且仅当 a<c, b<d,或者 b<c, a<d(相当于把矩形 X 旋转了 90°).例如 (1, 5) 可以嵌套在 (6, 2) 内,但不能嵌套在 (3, 4) 内. 你的任务是选出尽量多的矩形,使得除了最后一个之外,每一个矩形都可以嵌套在下一个矩形内. Input 第一…

传送门 Description 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 cha…

最小编辑距离的定义:编辑距离(Edit Distance),又称Levenshtein距离.是指两个字串之间,由一个转成还有一个所需的最少编辑操作次数.许可的编辑操作包含将一个字符替换成还有一个字符.插入一个字符,删除一个字符. 比如将kitten一字转成sitting: sitten(k→s) sittin(e→i) sitting(→g) 年提出这个概念. Thewords `computer' and `commuter' are very similar, and a change of…

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) Repla…

题目链接:https://leetcode.com/problems/edit-distance/ 题意:求字符串的最短编辑距离,就是有三个操作,插入一个字符.删除一个字符.修改一个字符,最终让两个字符串相等. DP,定义两个字符串a和b,dp(i,j)为截至ai-1和bj-1时的最短编辑距离. 当ai-1=bi-1的时候,有dp(i,j)=min(dp(i,j),dp(i-1,j-1)),对应不做任何操作: 不相等的时候会有dp(i,j)=min(dp(i,j),dp(i-1,j-1)+1),…

字符序列的子序列是指从给定字符序列中随意地(不一定连续)去掉若干个字符(可能一个也不去掉)后所形成的字符序列.令给定的字符序列X=“x0,x1,…,xm-1”,序列Y=“y0,y1,…,yk-1”是X的子序列,存在X的一个严格递增下标序列<i0,i1,…,ik-1>,使得对所有的j=0,1,…,k-1,有xij = yj.例如,X=“ABCBDAB”,Y=“BCDB”是X的一个子序列.对给定的两个字符序列,求出他们最长的公共子序列长度,以及最长公共子序列个数. Solution 这题其实就是让…

Description The branch of mathematics called number theory is about properties of numbers. One of the areas that has captured the interest of number theoreticians for thousands of years is the question of primality. A prime number is a number that is…

Level:   Hard 题目描述: Given two words word1 and word2, find the minimum number of operations required to convert word1 to word2. You have the following 3 operations permitted on a word: Insert a character Delete a character Replace a character Example…

题目 Source http://acm.hdu.edu.cn/showproblem.php?pid=5812 Description In number theory, a prime is a positive integer greater than 1 that has no positive divisors other than 1 and itself. The distance between two positive integers x and y, denoted by…