2017 年 7月随笔档案 - Beserious

103. Binary Tree Zigzag Level Order Traversal

摘要：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 阅读全文

posted @ 2017-07-31 15:04 Beserious 阅读(126) 评论(0) 推荐(0) 编辑

leetcode 226. Invert Binary Tree

摘要：Invert a binary tree. to . 阅读全文

posted @ 2017-07-30 20:26 Beserious 阅读(126) 评论(0) 推荐(0) 编辑

leetcode 520. Detect Capital

摘要：Given a word, you need to judge whether the usage of capitals in it is right or not. We define the usage of capitals in a word to be right when one of 阅读全文

posted @ 2017-07-30 19:59 Beserious 阅读(139) 评论(0) 推荐(0) 编辑

#1542 : 无根数变有根树

摘要：时间限制:10000ms 单点时限:1000ms 内存限制:256MB 时间限制:10000ms 单点时限:1000ms 内存限制:256MB 描述给定一棵包含 N 个节点的无根树，小Hi想知道如果指定其中某个节点 K 为根，那么每个节点的父节点是谁？输入第一行包含一个整数 N 和 K。1 ≤ 阅读全文

posted @ 2017-07-30 17:25 Beserious 阅读(222) 评论(0) 推荐(0) 编辑

#1543 : SCI表示法

摘要：时间限制:10000ms 单点时限:1000ms 内存限制:256MB 时间限制:10000ms 单点时限:1000ms 内存限制:256MB 描述每一个正整数 N 都能表示成若干个连续正整数的和，例如10可以表示成1+2+3+4，15可以表示成4+5+6，8可以表示成8本身。我们称这种表示方法为阅读全文

posted @ 2017-07-30 17:24 Beserious 阅读(503) 评论(0) 推荐(0) 编辑

leetcode 414. Third Maximum Number

摘要：Given a non-empty array of integers, return the third maximum number in this array. If it does not exist, return the maximum number. The time complexi 阅读全文

posted @ 2017-07-29 19:00 Beserious 阅读(138) 评论(0) 推荐(0) 编辑

leetcode 532. K-diff Pairs in an Array

摘要：Given an array of integers and an integer k, you need to find the number of unique k-diff pairs in the array. Here a k-diff pair is defined as an inte 阅读全文

posted @ 2017-07-29 15:30 Beserious 阅读(173) 评论(0) 推荐(0) 编辑

leetcode 581. Shortest Unsorted Continuous Subarray

摘要：Given an integer array, you need to find one continuous subarray that if you only sort this subarray in ascending order, then the whole array will be 阅读全文

posted @ 2017-07-29 12:41 Beserious 阅读(136) 评论(0) 推荐(0) 编辑

leetcode 605. Can Place Flowers

摘要：Suppose you have a long flowerbed in which some of the plots are planted and some are not. However, flowers cannot be planted in adjacent plots - they 阅读全文

posted @ 2017-07-29 10:17 Beserious 阅读(374) 评论(0) 推荐(0) 编辑

leetcode 219. Contains Duplicate II

摘要：Given an array of integers and an integer k, find out whether there are two distinct indices i and j in the array such that nums[i] = nums[j] and the 阅读全文

posted @ 2017-07-29 09:35 Beserious 阅读(149) 评论(0) 推荐(0) 编辑

leetcode 283. Move Zeroes

摘要：Given an array nums, write a function to move all 0's to the end of it while maintaining the relative order of the non-zero elements. For example, giv 阅读全文

posted @ 2017-07-28 17:21 Beserious 阅读(151) 评论(0) 推荐(0) 编辑

leetcode 217. Contains Duplicate

摘要：Given an array of integers, find if the array contains any duplicates. Your function should return true if any value appears at least twice in the arr 阅读全文

posted @ 2017-07-28 16:34 Beserious 阅读(196) 评论(0) 推荐(0) 编辑

leetcode 628. Maximum Product of Three Numbers

摘要：Given an integer array, find three numbers whose product is maximum and output the maximum product. Example 1: Example 2: Note: 排序，然后前后枚举一下就行了 3种情况。或阅读全文

posted @ 2017-07-28 16:22 Beserious 阅读(143) 评论(0) 推荐(0) 编辑

leetcode 268. Missing Number

摘要：Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing from the array. For example,Given nums = [0, 1, 阅读全文

posted @ 2017-07-28 16:03 Beserious 阅读(140) 评论(0) 推荐(0) 编辑

448. Find All Numbers Disappeared in an Array

摘要：Given an array of integers where 1 ≤ a[i] ≤ n (n = size of array), some elements appear twice and others appear once. Find all the elements of [1, n] 阅读全文

posted @ 2017-07-28 15:58 Beserious 阅读(146) 评论(0) 推荐(0) 编辑

leetcode 485. Max Consecutive Ones

摘要：Given a binary array, find the maximum number of consecutive 1s in this array. Example 1: Note: The input array will only contain 0 and 1. The length 阅读全文

posted @ 2017-07-28 12:09 Beserious 阅读(144) 评论(0) 推荐(0) 编辑

496. Next Greater Element I

摘要：You are given two arrays (without duplicates) nums1 and nums2 where nums1’s elements are subset of nums2. Find all the next greater numbers for nums1' 阅读全文

posted @ 2017-07-28 11:39 Beserious 阅读(132) 评论(0) 推荐(0) 编辑

leetcode 463. Island Perimeter

摘要：You are given a map in form of a two-dimensional integer grid where 1 represents land and 0 represents water. Grid cells are connected horizontally/ve 阅读全文

posted @ 2017-07-28 10:19 Beserious 阅读(133) 评论(0) 推荐(0) 编辑

leetcode 637. Average of Levels in Binary Tree

摘要：Given a non-empty binary tree, return the average value of the nodes on each level in the form of an array. Example 1: Note: 阅读全文

posted @ 2017-07-28 10:03 Beserious 阅读(165) 评论(0) 推荐(0) 编辑

412. Fizz Buzz

摘要：Write a program that outputs the string representation of numbers from 1 to n. But for multiples of three it should output “Fizz” instead of the numbe 阅读全文

posted @ 2017-07-28 09:55 Beserious 阅读(177) 评论(0) 推荐(0) 编辑

leetcode 566. Reshape the Matrix

摘要：In MATLAB, there is a very useful function called 'reshape', which can reshape a matrix into a new one with different size but keep its original data. 阅读全文

posted @ 2017-07-28 09:42 Beserious 阅读(155) 评论(0) 推荐(0) 编辑

leetcode 575. Distribute Candies

摘要：Given an integer array with even length, where different numbers in this array represent different kinds of candies. Each number means one candy of th 阅读全文

posted @ 2017-07-28 09:32 Beserious 阅读(219) 评论(0) 推荐(0) 编辑

344. Reverse String

摘要：Write a function that takes a string as input and returns the string reversed. Example:Given s = "hello", return "olleh". 反转字符串，逼我不用 reverse 阅读全文

posted @ 2017-07-27 22:02 Beserious 阅读(84) 评论(0) 推荐(0) 编辑

557. Reverse Words in a String III

摘要：Given a string, you need to reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order. E 阅读全文

posted @ 2017-07-27 21:40 Beserious 阅读(160) 评论(0) 推荐(0) 编辑

500. Keyboard Row

摘要：Given a List of words, return the words that can be typed using letters of alphabet on only one row's of American keyboard like the image below. Examp 阅读全文

posted @ 2017-07-27 21:21 Beserious 阅读(157) 评论(0) 推荐(0) 编辑

476. Number Complement

摘要：Given a positive integer, output its complement number. The complement strategy is to flip the bits of its binary representation. Note: Example 1: Exa 阅读全文

posted @ 2017-07-27 20:15 Beserious 阅读(134) 评论(0) 推荐(0) 编辑

561. Array Partition I

摘要：Given an array of 2n integers, your task is to group these integers into n pairs of integer, say (a1, b1), (a2, b2), ..., (an, bn) which makes sum of 阅读全文

posted @ 2017-07-27 19:45 Beserious 阅读(116) 评论(0) 推荐(0) 编辑

617. Merge Two Binary Trees

摘要：Given two binary trees and imagine that when you put one of them to cover the other, some nodes of the two trees are overlapped while the others are n 阅读全文

posted @ 2017-07-27 17:04 Beserious 阅读(145) 评论(0) 推荐(0) 编辑

461. Hamming Distance

摘要：The Hamming distance between two integers is the number of positions at which the corresponding bits are different. Given two integers x and y, calcul 阅读全文

posted @ 2017-07-27 12:45 Beserious 阅读(186) 评论(0) 推荐(0) 编辑

160. Intersection of Two Linked Lists

摘要：Write a program to find the node at which the intersection of two singly linked lists begins. For example, the following two linked lists: begin to in 阅读全文

posted @ 2017-07-26 13:28 Beserious 阅读(134) 评论(0) 推荐(0) 编辑

169. Majority Element

摘要：Given an array of size n, find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times. You may assume that the 阅读全文

posted @ 2017-07-26 12:14 Beserious 阅读(128) 评论(0) 推荐(0) 编辑

171. Excel Sheet Column Number

摘要：Related to question Excel Sheet Column Title Given a column title as appear in an Excel sheet, return its corresponding column number. For example: 从2 阅读全文

posted @ 2017-07-26 08:07 Beserious 阅读(181) 评论(0) 推荐(0) 编辑

168. Excel Sheet Column Title

摘要：Given a positive integer, return its corresponding column title as appear in an Excel sheet. For example: 其实类似26进制数阅读全文

posted @ 2017-07-26 07:58 Beserious 阅读(133) 评论(0) 推荐(0) 编辑

189. Rotate Array

摘要：Rotate an array of n elements to the right by k steps. For example, with n = 7 and k = 3, the array [1,2,3,4,5,6,7] is rotated to [5,6,7,1,2,3,4]. Not 阅读全文

posted @ 2017-07-25 18:35 Beserious 阅读(103) 评论(0) 推荐(0) 编辑

172. Factorial Trailing Zeroes

摘要：Given an integer n, return the number of trailing zeroes in n!. Note: Your solution should be in logarithmic time complexity. 求n得阶层，末尾0的个数老问题了，统计2,5的阅读全文

posted @ 2017-07-25 15:21 Beserious 阅读(71) 评论(0) 推荐(0) 编辑

176. Second Highest Salary

摘要：Write a SQL query to get the second highest salary from the Employee table. For example, given the above Employee table, the query should return 200 a 阅读全文

posted @ 2017-07-25 12:28 Beserious 阅读(115) 评论(0) 推荐(0) 编辑

167. Two Sum II - Input array is sorted (二分ortwo-pointer)

摘要：Given an array of integers that is already sorted in ascending order, find two numbers such that they add up to a specific target number. The function 阅读全文

posted @ 2017-07-25 11:54 Beserious 阅读(117) 评论(0) 推荐(0) 编辑

155. Min Stack

摘要：Design a stack that supports push, pop, top, and retrieving the minimum element in constant time. push(x) -- Push element x onto stack. pop() -- Remov 阅读全文

posted @ 2017-07-25 11:12 Beserious 阅读(141) 评论(0) 推荐(0) 编辑

141. Linked List Cycle

摘要：Given a linked list, determine if it has a cycle in it. Follow up:Can you solve it without using extra space? 一个+1 一个+2 看看能不能相遇。注意代码不要写乱了...以后尽量用p1 p2 阅读全文

posted @ 2017-07-24 20:38 Beserious 阅读(116) 评论(0) 推荐(0) 编辑

136. Single Number

摘要：Given an array of integers, every element appears twice except for one. Find that single one. Note:Your algorithm should have a linear runtime complex 阅读全文

posted @ 2017-07-24 17:36 Beserious 阅读(118) 评论(0) 推荐(0) 编辑

125. Valid Palindrome

摘要：Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases. For example,"A man, a plan, a canal: Pan 阅读全文

posted @ 2017-07-24 17:30 Beserious 阅读(144) 评论(0) 推荐(0) 编辑

122. Best Time to Buy and Sell Stock II

摘要：Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may comple 阅读全文

posted @ 2017-07-24 16:09 Beserious 阅读(129) 评论(0) 推荐(0) 编辑

121. Best Time to Buy and Sell Stock

摘要：Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted to complete at most one transaction 阅读全文

posted @ 2017-07-24 14:54 Beserious 阅读(132) 评论(0) 推荐(0) 编辑

119. Pascal's Triangle II

摘要：Given an index k, return the kth row of the Pascal's triangle. For example, given k = 3,Return [1,3,3,1]. Note:Could you optimize your algorithm to us 阅读全文

posted @ 2017-07-24 12:48 Beserious 阅读(166) 评论(0) 推荐(0) 编辑

118. Pascal's Triangle

摘要：Given numRows, generate the first numRows of Pascal's triangle. For example, given numRows = 5,Return 注意左右的边界赋值阅读全文

posted @ 2017-07-24 12:19 Beserious 阅读(124) 评论(0) 推荐(0) 编辑

112. Path Sum

摘要：Given a binary tree and a sum, determine if the tree has a root-to-leaf path such that adding up all the values along the path equals the given sum. F 阅读全文

posted @ 2017-07-24 11:54 Beserious 阅读(110) 评论(0) 推荐(0) 编辑

111. Minimum Depth of Binary Tree

摘要：Given a binary tree, find its minimum depth. The minimum depth is the number of nodes along the shortest path from the root node down to the nearest l 阅读全文

posted @ 2017-07-24 11:30 Beserious 阅读(110) 评论(0) 推荐(0) 编辑

110. Balanced Binary Tree

摘要：Given a binary tree, determine if it is height-balanced. For this problem, a height-balanced binary tree is defined as a binary tree in which the dept 阅读全文

posted @ 2017-07-24 10:48 Beserious 阅读(123) 评论(0) 推荐(0) 编辑

108. Convert Sorted Array to Binary Search Tree

摘要：Given an array where elements are sorted in ascending order, convert it to a height balanced BST. 给定有序数组构造二叉搜索树。考虑到二叉搜索树的性质（中序遍历二叉搜索树可以得到一个排序好的数组）构造的阅读全文

posted @ 2017-07-23 17:30 Beserious 阅读(108) 评论(0) 推荐(0) 编辑

107.Binary Tree Level Order Traversal II

摘要：Given a binary tree, return the bottom-up level order traversal of its nodes' values. (ie, from left to right, level by level from leaf to root). For 阅读全文

posted @ 2017-07-22 17:29 Beserious 阅读(125) 评论(0) 推荐(0) 编辑

104. Maximum Depth of Binary Tree

摘要：Given a binary tree, find its maximum depth. The maximum depth is the number of nodes along the longest path from the root node down to the farthest l 阅读全文

posted @ 2017-07-21 18:13 Beserious 阅读(108) 评论(0) 推荐(0) 编辑

101. Symmetric Tree

摘要：Given a binary tree, check whether it is a mirror of itself (ie, symmetric around its center). For example, this binary tree [1,2,2,3,4,4,3] is symmet 阅读全文

posted @ 2017-07-21 17:54 Beserious 阅读(114) 评论(0) 推荐(0) 编辑

100. Same Tree

摘要：Given two binary trees, write a function to check if they are equal or not. Two binary trees are considered equal if they are structurally identical a 阅读全文

posted @ 2017-07-21 15:53 Beserious 阅读(121) 评论(0) 推荐(0) 编辑

88. Merge Sorted Array

摘要：Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array. Note:You may assume that nums1 has enough space (size tha 阅读全文

posted @ 2017-07-21 15:29 Beserious 阅读(98) 评论(0) 推荐(0) 编辑

83. Remove Duplicates from Sorted List

摘要：Given a sorted linked list, delete all duplicates such that each element appear only once. For example,Given 1->1->2, return 1->2.Given 1->1->2->3->3, 阅读全文

posted @ 2017-07-20 19:08 Beserious 阅读(110) 评论(0) 推荐(0) 编辑

70. Climbing Stairs

摘要：You are climbing a stair case. It takes n steps to reach to the top. Each time you can either climb 1 or 2 steps. In how many distinct ways can you cl 阅读全文

posted @ 2017-07-20 18:05 Beserious 阅读(136) 评论(0) 推荐(0) 编辑

69. Sqrt(x)

摘要：Implement int sqrt(int x). Compute and return the square root of x. 二分可解这里是关于二分的一些总结：首先，如果题目属于"二分值越大越符合条件"，即要求符合条件的最小值，那就是while(r>l){mid=(l+r)/2。。。} 阅读全文

posted @ 2017-07-20 16:32 Beserious 阅读(120) 评论(0) 推荐(0) 编辑

67. Add Binary

摘要：Given two binary strings, return their sum (also a binary string). For example,a = "11"b = "1"Return "100". 模拟二进制相加，右对齐，然后每位相加....不知道字符串左加和右加对性能有没有影响阅读全文

posted @ 2017-07-20 13:45 Beserious 阅读(114) 评论(0) 推荐(0) 编辑

66. Plus One

摘要：Given a non-negative integer represented as a non-empty array of digits, plus one to the integer. You may assume the integer do not contain any leadin 阅读全文

posted @ 2017-07-20 11:51 Beserious 阅读(159) 评论(0) 推荐(0) 编辑

58. Length of Last Word

摘要：Given a string s consists of upper/lower-case alphabets and empty space characters ' ', return the length of last word in the string. If the last word 阅读全文

posted @ 2017-07-20 11:48 Beserious 阅读(94) 评论(0) 推荐(0) 编辑

53. Maximum Subarray

摘要：Find the contiguous subarray within an array (containing at least one number) which has the largest sum. For example, given the array [-2,1,-3,4,-1,2, 阅读全文

posted @ 2017-07-20 08:13 Beserious 阅读(117) 评论(0) 推荐(0) 编辑

38. Count and Say

摘要：The count-and-say sequence is the sequence of integers with the first five terms as following: 1. 1 2. 11 3. 21 4. 1211 5. 111221 1 is read off as "on 阅读全文

posted @ 2017-07-19 21:03 Beserious 阅读(132) 评论(0) 推荐(0) 编辑

35. Search Insert Position

摘要：Given a sorted array and a target value, return the index if the target is found. If not, return the index where it would be if it were inserted in or 阅读全文

posted @ 2017-07-19 20:08 Beserious 阅读(91) 评论(0) 推荐(0) 编辑

28. Implement strStr()

摘要：Implement strStr(). Returns the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack. 字符串Rabin--Karp算法。滚动哈希，时间阅读全文

posted @ 2017-07-19 19:43 Beserious 阅读(92) 评论(0) 推荐(0) 编辑

27. Remove Element

摘要：Given an array and a value, remove all instances of that value in place and return the new length. Do not allocate extra space for another array, you 阅读全文

posted @ 2017-07-18 16:12 Beserious 阅读(105) 评论(0) 推荐(0) 编辑

26. Remove Duplicates from Sorted Array

摘要：Given a sorted array, remove the duplicates in place such that each element appear only once and return the new length. Do not allocate extra space fo 阅读全文

posted @ 2017-07-18 16:00 Beserious 阅读(78) 评论(0) 推荐(0) 编辑

21. Merge Two Sorted Lists

摘要：Merge two sorted linked lists and return it as a new list. The new list should be made by splicing together the nodes of the first two lists. 注意边界，注意边阅读全文

posted @ 2017-07-18 15:47 Beserious 阅读(128) 评论(0) 推荐(0) 编辑

20. Valid Parentheses

摘要：Given a string containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid. The brackets must close in the 阅读全文

posted @ 2017-07-18 13:55 Beserious 阅读(115) 评论(0) 推荐(0) 编辑

14. Longest Common Prefix

摘要：Write a function to find the longest common prefix string amongst an array of strings. 找出，给出的一堆字符串的公共前缀。两个两个比较阅读全文

posted @ 2017-07-17 20:09 Beserious 阅读(110) 评论(0) 推荐(0) 编辑

13. Roman to Integer

摘要：Given a roman numeral, convert it to an integer. Input is guaranteed to be within the range from 1 to 3999. 给出罗马数字输出对应的阿拉伯数字。思路来自29的罗马数字观看罗马数字构造规则(h 阅读全文

posted @ 2017-07-17 19:36 Beserious 阅读(130) 评论(0) 推荐(0) 编辑

9. Palindrome Number

摘要：Determine whether an integer is a palindrome. Do this without extra space. 就是判断反转后的整数和反转之前的整数是否相等阅读全文

posted @ 2017-07-17 16:55 Beserious 阅读(93) 评论(0) 推荐(0) 编辑

7. Reverse Integer

摘要：Reverse digits of an integer. Example1: x = 123, return 321Example2: x = -123, return -321 Note:The input is assumed to be a 32-bit signed integer. Yo 阅读全文

posted @ 2017-07-17 14:45 Beserious 阅读(102) 评论(0) 推荐(0) 编辑

机器学习面试常见问题

摘要：（1）SVM/LR/GBDT/EM的原理以及公式推导（2）RF和GDBT的区别；GDBT，XGBOOST的区别，从底层原理去分析（3）决策树处理连续值方法（4）解释一下原问题和对偶问题（5）什么是过拟合，以及解决方案（6）什么是正则项，L1范式，L2范式区别是什么，各自用在什么地方？（7 阅读全文

posted @ 2017-07-13 22:38 Beserious 阅读(303) 评论(0) 推荐(0) 编辑

ROS人脸检测使用webcam实现

摘要：github地址https://github.com/ngunauj/facedetection 熟悉ros环境。ubuntu16.04 + ros kinetic版本。使用笔记本自带摄像头，完成人脸的实时检测。代码可能会更改，具体以github上的代码为主。 camera_driver代码在人脸阅读全文

posted @ 2017-07-10 15:48 Beserious 阅读(1846) 评论(2) 推荐(0) 编辑

1. Two Sum

摘要：Given an array of integers, return indices of the two numbers such that they add up to a specific target. You may assume that each input would have ex 阅读全文

posted @ 2017-07-04 22:21 Beserious 阅读(133) 评论(0) 推荐(0) 编辑