题目:http://poj.org/problem?id=3267 题意:给定一个字符串,又给n个单词,求最少删除字符串里几个字母,能匹配到n个单词里 #include <iostream> #include<cstdio> #include<cstring> #include<cstdlib> #include<stack> #include<queue> #include<iomanip> #include<cm…

https://vjudge.net/problem/POJ-3267 题意 给一个长度为L的字符串,以及有W个单词的词典.问最少需要从主串中删除几个字母,使其可以由词典的单词组成. 分析 状态设置很关键,设dp[i]表示以i为起始的后缀需要删去字母的最小数目.那么根据状态,必须从后往前遍历,现在考虑往前加入一个新字母,会发生什么呢?第一,考虑最坏情况,就是加进来的字母没有用处,即转移成dp[i+1]+1;第二,就是加入这个字母后,以这个字母开始的串可以删去一些字母从而符合要求,那么此时就要计算…

http://poj.org/problem?id=3267 The Cow Lexicon Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 9380   Accepted: 4469 Description Few know that the cows have their own dictionary with W (1 ≤ W ≤ 600) words, each containing no more 25 of t…

题目链接: http://poj.org/problem?id=3267 从后往前遍历,dp[i]表示第i个字符到最后一个字符删除的字符个数. 状态转移方程为: dp[i] = dp[i+1] + 1;                                                 //当不能匹配时 dp[i] = std::min(dp[i], dp[msg] + (msg-i) - len[j]);  //当匹配时. 第i个字符到第msg个字符之间一共有msg-i个字符,减去…

题 Description The cows don't use actual bowling balls when they go bowling. They each take a number (in the range 0..99), though, and line up in a standard bowling-pin-like triangle like this: 7 3 8 8 1 0 2 7 4 4 4 5 2 6 5 Then the other cows travers…

传送门 f[i] 表示前 i 个字符去掉多少个 的最优解 直接暴力DP ——代码 #include <cstdio> #include <cstring> #include <iostream> ]; ], a[][]; inline int read() { , f = ; char ch = getchar(); ; ) + (x << ) + ch - '; return x * f; } inline int min(int x, int y) {…

POJ 3268 Silver Cow Party (最短路径) Description One cow from each of N farms (1 ≤ N ≤ 1000) conveniently numbered 1..N is going to attend the big cow party to be held at farm #X (1 ≤ X ≤ N). A total of M (1 ≤ M ≤ 100,000) unidirectional (one-way roads c…

继续大战dp.2018年11月30日修订,更新一下现在看到这个题目的理解(ps:就现在,poj又503了). 题意分析 这条题目的大意是这样的,问一字符串内最少删去多少的字符使其由给定的若干字符串构成.非常好的一道字符串dp题. 具体的dp解法是什么呢?考虑一下我们删去的这个过程.比如说这个式子 throw thraow 我们要不然删去a,要不然删去 “thraow”才能满足由第一个式子构成的这个条件(空串也算被第一个式子构造了).但是,程序如何知道删去a是使这俩个单词匹配的最优决策? 我们这样…

又见面了,还是原来的配方,还是熟悉的DP....直接秒了... The Cow Lexicon Time Limit: 2000MS Memory Limit: 65536K Total Submissions: 7316 Accepted: 3421 Description Few know that the cows have their own dictionary with W (1 ≤ W ≤ 600) words, each containing no more 25 of the…

The Cow Lexicon Time Limit: 2000MS   Memory Limit: 65536K Total Submissions: 8167   Accepted: 3845 Description Few know that the cows have their own dictionary with W (1 ≤ W ≤ 600) words, each containing no more 25 of the characters 'a'..'z'. Their c…