DFS 深搜专题 入门典例 -- 凌宸1642 深度优先搜索 是一种 枚举所有完整路径以遍历所有情况的搜索方法 ,使用 递归 可以很好的实现 深度优先搜索. 1 最大价值 题目描述 ​ 有 n 件物品,每件物品的重量为 w[i] , 价值为 c[i] .现在需要选出若干件物品放入一个容器为 V 的背包中,使得在选入背包的物品重量和不超过容量 V 的前提下 ,让背包中的物品的价值之和最大,求最大价值.(1 ≤ n≤ 20 ) 输入描述: ​ 第一行输入物品总数 n 和 背包容量 v . ​ 第二行…

[编程题] 黑白树 时间限制:1秒 空间限制:32768K 一棵n个点的有根树,1号点为根,相邻的两个节点之间的距离为1.树上每个节点i对应一个值k[i].每个点都有一个颜色,初始的时候所有点都是白色的. 你需要通过一系列操作使得最终每个点变成黑色.每次操作需要选择一个节点i,i必须是白色的,然后i到根的链上(包括节点i与根)所有与节点i距离小于k[i]的点都会变黑,已经是黑的点保持为黑.问最少使用几次操作能把整棵树变黑. 输入描述: 第一行一个整数n (1 ≤ n ≤ 10^5) 接下来n-1…

PAT (Advanced Level) Practice 1046 Shortest Distance (20 分) 凌宸1642 题目描述: The task is really simple: given N exits on a highway which forms a simple cycle, you are supposed to tell the shortest distance between any pair of exits. 译:你的任务很简单:给定 N 个出口,形成…

PAT (Advanced Level) Practice 1042 Shuffling Machine (20 分) 凌宸1642 题目描述: Shuffling is a procedure used to randomize a deck of playing cards. Because standard shuffling techniques are seen as weak, and in order to avoid "inside jobs" where employ…

PAT (Advanced Level) Practice 1041 Be Unique (20 分) 凌宸1642 题目描述: Being unique is so important to people on Mars that even their lottery is designed in a unique way. The rule of winning is simple: one bets on a number chosen from [1,10 4 ]. The first…

PAT (Advanced Level) Practice 1035 Password (20 分) 凌宸1642 题目描述: To prepare for PAT, the judge sometimes has to generate random passwords for the users. The problem is that there are always some confusing passwords since it is hard to distinguish 1 (o…

PAT (Advanced Level) Practice 1031 Hello World for U (20 分) 凌宸1642 题目描述: Given any string of N (≥5) characters, you are asked to form the characters into the shape of U. For example, helloworld can be printed as: h d e l l r lowo That is, the charact…

PAT (Advanced Level) Practice 1027 Colors in Mars (20 分) 凌宸1642 题目描述: People in Mars represent the colors in their computers in a similar way as the Earth people. That is, a color is represented by a 6-digit number, where the first 2 digits are for R…

PAT (Advanced Level) Practice 1023 Have Fun with Numbers (20 分) 凌宸1642 题目描述: Notice that the number 123456789 is a 9-digit number consisting exactly the numbers from 1 to 9, with no duplication. Double it we will obtain 246913578, which happens to be…

PAT (Advanced Level) Practice 1019 General Palindromic Number (20 分) 凌宸1642 题目描述: A number that will be the same when it is written forwards or backwards is known as a Palindromic Number. For example, 1234321 is a palindromic number. All single digit…