[topcoder]ZigZag】的更多相关文章

题目链接:https://community.topcoder.com/stat?c=problem_statement&pm=1259&rd=4493 题意:给一串数字,求出最长的波动序列.波动的定义是一个数相邻的两个数同时比他大或者同时比他小,形象的看成一个波动的三角函数吧. 定义dp(i)为到第i个数字时的最长波动序列长度,我们发现仅有一维的数组是存不下状态的,还应该再维护一个量,那就是第i个数字的时候他是波峰还是波谷.于是dp数组扩展成了dp(i,k),k可以取0或1分别表示是波峰…
http://community.topcoder.com/stat?c=problem_statement&pm=1259&rd=4493 动态规划题.如果不用DP,暴力的应当在2^n*n的复杂度吧.动态规划现在我的思维还老停留在一维而且没有第二层循环.但其实如果一开始的复杂度很高,稍微有几个循环,指数级别,一点问题没有. 题目描述:给出n个数:A[1], A[2], ... , A[n],求最长的子序列的长度,子序列中相邻数之间的差值是正负交替出现的.f1[i]表示 最后一个数是A[i…
题目来源:http://community.topcoder.com/stat?c=problem_statement&pm=1259&rd=4493 类似于求最长子串的方法.dp[0][i]表示以 元素sequence[i] 结尾的且它比子串中前一个数小的 最大子串,dp[1][i] 表示以 元素sequence[i] 结尾的且它比子串中前一个数大的 最大子串. 代码如下: #include <algorithm> #include <iostream> #inc…
Given two 1d vectors, implement an iterator to return their elements alternately. For example, given two 1d vectors: v1 = [1, 2] v2 = [3, 4, 5, 6] By calling next repeatedly until hasNext returns false, the order of elements returned by next should b…
Given a binary tree, return the zigzag level order traversal of its nodes' values. (ie, from left to right, then right to left for the next level and alternate between). For example:Given binary tree {3,9,20,#,#,15,7}, 3 / \ 9 20 / \ 15 7 return its…
The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility) P A H N A P L S I I G Y I R And then read line by line: "PAHNAPLSII…
题目简述 The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility) P A H N A P L S I I G Y I R And then read line by line: "PAHNA…
在分析Avro源码时,发现Avro为了对int.long类型数据压缩,采用Protocol Buffers的ZigZag编码(Thrift也采用了ZigZag来压缩整数). 1. 补码编码 为了便于后面的分析,我们先回顾下几个概念: 原码:最高位为符号位,剩余位表示绝对值: 反码:除符号位外,对原码剩余位依次取反: 补码:对于正数,补码为其自身:对于负数,除符号位外对原码剩余位依次取反然后+1. 补码解决了原码中\(0\)存在两种编码的问题: \[ 0=[0000 \enspace 0000]_…
问题: The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility) P   A   H   N A P L S I I G Y   I   R And then read line by line: &q…
题目: The string "PAYPALISHIRING" is written in a zigzag pattern on a given number of rows like this: (you may want to display this pattern in a fixed font for better legibility) P A H N A P L S I I G Y I R And then read line by line: "PAHNAP…