意甲冠军  是否可以由串来推断a,b字符不改变其相对为了获取字符串的组合c 本题有两种解法  DP或者DFS 考虑DP  令d[i][j]表示是否能有a的前i个字符和b的前j个字符组合得到c的前i+j个字符  值为0或者1  那么有d[i][j]=(d[i-1][j]&&a[i]==c[i+j])||(d[i][j-1]&&b[i]==c[i+j])   a,b的下标都是从1開始的  注意0的初始化 #include<cstdio> #include<cs…

Zipper Given three strings, you are to determine whether the third string can be formed by combining the characters in the first two strings. The first two strings can be mixed arbitrarily, but each must stay in its original order. For example, consi…

题意:给定三个串,问c串是否能由a,b串任意组合在一起组成,但注意a,b串任意组合需要保证a,b原串的顺序 例如ab,cd可组成acbd,但不能组成adcb. 分析:对字符串上的dp还是不敏感啊,虽然挺裸的....dp[i][j] 表示a串前i个,b串前j个字母能组成c串前i+j个字母.所以dp[lena-1][lenb-1] = 1; 就行了. 从后往前找就很好找了,从c串最后一个字符开始递归搜索. #include <cstdio> #include <iostream> #i…

http://poj.org/problem?id=2192 Zipper Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 17585   Accepted: 6253 Description Given three strings, you are to determine whether the third string can be formed by combining the characters in the…

HDOJ 1501 Zipper [简单DP] Problem Description Given three strings, you are to determine whether the third string can be formed by combining the characters in the first two strings. The first two strings can be mixed arbitrarily, but each must stay in i…

HDOJ 1501 Zipper [DP][DFS+剪枝] Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/32768 K (Java/Others) Total Submission(s): 10886 Accepted Submission(s): 3925 Problem Description Given three strings, you are to determine whether the third str…

题目大意 给定三个字符串s1,s2,s3,判断由s1和s2的字符能否组成字符串s3,并且要求组合后的字符串必须是s1,s2中原来的顺序. 题解 用dp[i][j]表示s1的前i个字符和s2的前j个字符能否组成s3的前i+j个字符,有两个子问题,dp[i-1][j]和dp[i][j-1],如果dp[i-1][j]为真并且s1[i]==s3[i+j]或者dp[i][j-1]为真并且s2[j]==s3[i+j]则dp[i][j]=true;否则dp[i][j]=false; 代码: #include<…

题目链接:http://poj.org/problem?id=2192 思路分析:该问题可以看做dp问题,同时也可以使用dfs搜索求解,这里使用dp解法: 设字符串StrA[0, 1, …, n]和StrB[0,1, .., m]构成字符串Str[0, 1, … , m + n + 1]; 1)状态定义:dp[i, j]表示字符串StrA[0, 1, …, i-1]和字符串StrB[0, 1, .., j-1]构成字符串Str[0, 1, …, i+j-1]: 2)状态转移:如果dp[i-1][…

Problem Description Given three strings, you are to determine whether the third string can be formed by combining the characters in the first two strings. The first two strings can be mixed arbitrarily, but each must stay in its original order. For e…

遇到双塔DP,写一下. flag是为了避免memset多次导致的时间浪费. #include<cstdio> #include<cstdlib> #include<iostream> #include<cstring> using namespace std; char x[410],y[410],z[410]; int map[410][410],L,Lx;//410=210+x bool _find(int flag) { for(int i=1;i&l…