POJ1458 Common Subsequence(最长公共子序列LCS) http://poj.org/problem?id=1458 题意: 给你两个字符串, 要你求出两个字符串的最长公共子序列长度. 分析: 本题不用输出子序列,非常easy,直接处理就可以. 首先令dp[i][j]==x表示A串的前i个字符和B串的前j个字符的最长公共子序列长度为x. 初始化: dp全为0. 状态转移: IfA[i]==B[j] then dp[i][j]= dp[i-1][j-1]+1 else dp[…

题目大意:求两个字符串的最长公共子序列 题目思路:dp[i][j] 表示第一个字符串前i位 和 第二个字符串前j位的最长公共子序列 #include<stdio.h> #include<string.h> #include<stdlib.h> #include<math.h> #include<iostream> #include<algorithm> #define INF 0x3f3f3f3f #define MAXSIZE 10…

本题大意:给出两个字符串,让你求出最长公共子序列的长度并输出. 本题思路:本题是经典的DP问题,由于是两个字符串,那么我们就用一个二维数组来进行区分,用dp[ i ][ j ]来表示在s1和s2中分别以i, j 结尾的子串中最长公共子序列的长度,很容易得出dp[i + 1] [j + 1] 的值只与dp[ i ][ j ] ,dp[i + 1][ j ] , dp[[ i ][ j + 1]的值有关,那么我们就可以列出状态转移方程. dp[ i + 1][j + 1] = s1[ i ] ==…

LCS #include<cstdio> #include<cstring> #include<algorithm> #include<iostream> #define clc(a,b) memset(a,b,sizeof(a)) #define LL long long #include<cmath> using namespace std; ][];//表示到i-1,j-1的最长公共长度 int main() { // freopen(&q…

Palindrome Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 56150   Accepted: 19398 Description A palindrome is a symmetrical string, that is, a string read identically from left to right as well as from right to left. You are to write a…

题意:给两个字符串,求这两个字符串的最长公共子序列的长度 因为之前集训的时候做过,所以现在即使会做也并不是什么稀奇的事,依旧为了自己的浅薄感到羞愧啊``` 解法就是通过两个字符串的每个字符互相比较,根据比较情况相同与否确定递推关系: dp [ i + 1 ] [ j + 1 ] 表示匹配到 a 字符串的第 i 个字符和 b 字符串的第 j 个字符时的最大匹配数,由于读字符串的时候我是从下标 0 读起的,但我需要用 dp [ 0 ] ,所以就都是加了一,否则也可以读入的时候直接从 a + 1 和…

http://poj.org/problem?id=1159 题意: 给出一个字符串,计算最少要插入多少个字符可以使得该串变为回文串. 思路: 计算出最长公共子序列,再用原长-LCS=所要添加的字符数. #include<iostream> #include<string> #include<cstring> #include<cstdio> #include<algorithm> using namespace std; + ; char s1…

Human Gene Functions Time Limit: 1000MS   Memory Limit: 10000K Total Submissions: 17805   Accepted: 9917 Description It is well known that a human gene can be considered as a sequence, consisting of four nucleotides, which are simply denoted by four…

Palindrome Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 53414   Accepted: 18449 Description A palindrome is a symmetrical string, that is, a string read identically from left to right as well as from right to left. You are to write a…

Palindrome Time Limit: 3000MS   Memory Limit: 65536K Total Submissions: 56273   Accepted: 19455 Description A palindrome is a symmetrical string, that is, a string read identically from left to right as well as from right to left. You are to write a…