D. Easy Problem dp(有衔接关系的dp(类似于分类讨论) ) 题意 给出一个串 给出删除每一个字符的代价问使得串里面没有hard的子序列需要付出的最小代价(子序列不连续也行) 思路 要满足hard 先要满足har 要满足har 先要满足ha 一次类推 这类问题的一个共同点是要每个地方都要满足一系列前置条件才能成立也就是说有衔接关系 所以如果是构造问题 那么dp数组加一维已经满足了几个,如果是删除问题dp数组加一维 切断了哪一个即可 所以我们可以设置dp数学 dp[i][1,2,3…

[链接] 我是链接,点我呀:) [题意] 让你将一个字符串删掉一些字符. 使得字符串中不包含子序列"hard" 删掉每个字符的代价已知为ai 让你求出代价最小的方法. [题解] 设dp[i][j]表示前i个字符,已经和"hard"匹配前j个的最小花费. 对于dp[i][j] 对s[i+1]分类讨论 ①s[i+1]不删 那么有两种情况 第一种:s[i+1]和"hard"的第j+1个字符匹配 第二种:..xxxxx不匹配 则分别转移到dp[i+1][…

Vasya is preparing a contest, and now he has written a statement for an easy problem. The statement is a string of length n consisting of lowercase Latin latters. Vasya thinks that the statement can be considered hard if it contains a subsequence har…

题目地址:CF1096D Easy Problem 比赛时高二dalaoLRZ提醒我是状压,然而,我还是没AC (汗 其实是一道很基础的线性dp \(f_{i,j}\) 表示序列第 \(i\) 个字符时对于 \(string\ st="hard"\) 的前缀 \(0\) ~ \(j-1\) 最小的ambiguity值 边界: \(f_0=0\) ,其它 \(f\) 值均为 \(∞\) 状态转移方程: 若 \(s_i≠st_{j-1}\) ,则 \(f_{i,j}=f_{i-1,j}\)…

An easy problem A Time Limit: 1000/1000MS (Java/Others) Memory Limit: 65535/65535KB (Java/Others) Problem Description N个数排成一列,Q个询问,每次询问一段区间内的数的极差是多少. Input 第一行两个整数N(1≤N≤50000),Q(1≤Q≤200000).接下来一行N个整数a1 a2 a3 -.an,(1≤ai≤1000000000).接下来Q行,每行两个整数L,R(1≤L…

Problem E Easy Problem from Rujia Liu? Though Rujia Liu usually sets hard problems for contests (for example, regional contests like Xi'an 2006, Beijing 2007 and Wuhan 2009, or UVa OJ contests like Rujia Liu's Presents 1 and 2), he occasionally sets…

图片大小以及dp和px关系一览表 说明:根据上表,我们应该很容易算出一张图片在不同手机上的宽和高是多少. 结论 从上表可以得出如下结论 1. 图片放在drawable中,等同于放在drawable-mdpi中,原因为:drawable目录不具有屏幕密度特性,所以采用基准值,即mdpi 2. 图片放在某个特定drawable中,比如drawable-hdpi,如果设备的屏幕密度高于当前drawable目录所代表的密度,则图片会被放大,否则会被缩小 放大或缩小比例 = 设备屏幕密度 / drawab…

An easy problem Time Limit:3000MS     Memory Limit:32768KB     64bit IO Format:%I64d & %I64u Submit Status Description When Teddy was a child , he was always thinking about some simple math problems ,such as “What it’s 1 cup of water plus 1 pile of d…

Easy Problem from Rujia Liu? Though Rujia Liu usually sets hard problems for contests (for example, regional contests like Xi'an 2006, Beijing 2007 and Wuhan 2009, or UVa OJ contests like Rujia Liu's Presents 1 and 2), he occasionally sets easy probl…

An Easy Problem?! Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 7837   Accepted: 1145 Description It's raining outside. Farmer Johnson's bull Ben wants some rain to water his flowers. Ben nails two wooden boards on the wall of his barn…