LeetCode Binary Search All In One
LeetCode Binary Search All In One
Binary Search
二分查找算法
https://leetcode-cn.com/problems/binary-search/
https://leetcode-cn.com/problems/binary-search/solution/er-fen-cha-zhao-by-leetcode/
复杂度分析
时间复杂度:\mathcal{O}(\log N)O(logN)。
空间复杂度:\mathcal{O}(1)O(1)。
LeetCode Binary Search Best Solutions in JavaScript
- 位运算
/**
* @param {number[]} nums
* @param {number} target
* @return {number}
*/
const search = (nums, target) => {
if(nums.length === 0){
return -1;
}
let lo = 0;
let hi = nums.length - 1;
while(lo <= hi){
// 位运算 12 >> 1 === 6
const mid = lo + ((hi - lo) >> 1);
if(nums[mid] === target){
return mid;
}else if(nums[mid] < target){
lo = mid + 1;
}else{
hi = mid - 1;
}
}
return -1;
};
- 经典双指针
/**
* @param {number[]} nums
* @param {number} target
* @return {number}
*/
var search = function(nums, target) {
let left = 0;
let right = nums.length-1
let middle
while(right >= left){
middle = Math.floor((left+right)/2)
const midval = nums[middle]
if(midval === target) return middle;
else if(midval > target) right = middle-1;
else left = middle +1;
}
return -1
};
bad
/**
* @param {number[]} nums
* @param {number} target
* @return {number}
*/
var search = function(nums, target) {
const findValue = (arr, target) => {
let result = -1;
let len = arr.length;
let index = Math.floor(len / 2);
let mid = arr[index];
let leftArr = arr.slice(0, index)
let rightArr = arr.slice(index + 1, len)
if(mid === target) {
result = nums.indexOf(mid);
} else {
if(mid > target) {
// left
result = findValue(leftArr, target)
}
if(mid < target) {
// right
result = findValue(rightArr, target)
}
}
return result;
}
return findValue(nums, target);
};
refs
https://leetcode.com/problemset/all/
https://leetcode-cn.com/problemset/all/
xgqfrms 2012-2020
www.cnblogs.com 发布文章使用:只允许注册用户才可以访问!
LeetCode Binary Search All In One的更多相关文章
- [LeetCode] Binary Search 二分搜索法
Given a sorted (in ascending order) integer array nums of n elements and a target value, write a fun ...
- LeetCode & Binary Search 解题模版
LeetCode & Binary Search 解题模版 In computer science, binary search, also known as half-interval se ...
- [LeetCode] Binary Search Tree Iterator 二叉搜索树迭代器
Implement an iterator over a binary search tree (BST). Your iterator will be initialized with the ro ...
- LeetCode Binary Search Tree Iterator
原题链接在这里:https://leetcode.com/problems/binary-search-tree-iterator/ Implement an iterator over a bina ...
- [Leetcode] Binary search -- 475. Heaters
Winter is coming! Your first job during the contest is to design a standard heater with fixed warm r ...
- 153. Find Minimum in Rotated Sorted Array(leetcode, binary search)
https://leetcode.com/problems/find-minimum-in-rotated-sorted-array/description/ leetcode 的题目,binary ...
- [Leetcode] Binary search, Divide and conquer--240. Search a 2D Matrix II
Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the follo ...
- [Leetcode] Binary search, DP--300. Longest Increasing Subsequence
Given an unsorted array of integers, find the length of longest increasing subsequence. For example, ...
- LeetCode: Binary Search Tree Iterator 解题报告
Binary Search Tree Iterator Implement an iterator over a binary search tree (BST). Your iterator wil ...
随机推荐
- navicat premium 11.0.17 破解版
下载地址: 链接:https://pan.baidu.com/s/1zBoKRAaQZb2p2weelJpKMQ 提取码:b8dd 一款功能强大的数据库管理工具Navicat Premiu ...
- Dubbo 总结:关于 Dubbo 的重要知识点
一 重要的概念 1.1 什么是 Dubbo? Apache Dubbo (incubating) |ˈdʌbəʊ| 是一款高性能.轻量级的开源Java RPC 框架,它提供了三大核心能力:面向接口的远 ...
- sourcetree注册
http://www.cnblogs.com/xiofee/p/sourcetree_pass_initialization_setup.html
- 一文入门Linux下gdb调试(一)
作者:良知犹存 转载授权以及围观:欢迎添加微信号:Conscience_Remains 总述 在window下我们习惯了IDE的各种调试按钮,说实话确实挺方便的,但到了Linux下,没有那么多的IDE ...
- Java ArrayList源码分析(含扩容机制等重点问题分析)
写在最前面 这个项目是从20年末就立好的 flag,经过几年的学习,回过头再去看很多知识点又有新的理解.所以趁着找实习的准备,结合以前的学习储备,创建一个主要针对应届生和初学者的 Java 开源知识项 ...
- [ZJOI2007]仓库建设(斜率dp优化)
前言 纪念一下我做的第二道斜率优化$dp$题,终于自己能把代码敲出来了,然而有很智障的$bug$,把$i$写成$q[i]$,找了半天QAQ.然后写$dp$公式并优化的能力稍微强了一点(自我感觉良好), ...
- hdu 2072 单词数(字符串)
题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=2072 题意 每行输入由小写字母和空格组成,统计每行中不同的单词数. 题解 题解一 比较简洁的解法,读入 ...
- 【noi 2.6_6046】数据包的调度机制(区间DP)
题意:给定一个队列延迟值为Di的任务,以任意顺序入栈和出栈,第K个出栈的延迟值为(K-1)*Di.问最小的延迟值. 解法:f[i][l]表示完成以第i个任务开始,长度为l,到第i+l-1个任务的最小延 ...
- 【noi 2.6_1808】最长公共子序列(DP)
题意:给2个字符串求其最大公共子序列的长度.解法:这个和一般的状态定义有点不一样,f[i][j]表示 str 前i位和 str2 前j的最大公共子序列的长度,而不是选 str 的第i位和 str2 的 ...
- 2020 ICPC Asia Taipei-Hsinchu Regional Problem H Optimization for UltraNet (二分,最小生成树,dsu计数)
题意:给你一张图,要你去边,使其成为一个边数为\(n-1\)的树,同时要求树的最小边权最大,如果最小边权最大的情况有多种,那么要求总边权最小.求生成树后的所有简单路径上的最小边权和. 题解:刚开始想写 ...