爱橙子的OK绷的专栏

问题描述：Compare two version numbers version1 and version2. If version1 > version2 return 1, if version1 < version2 return -1, otherwise return 0.You may assume that the version strings are non-empty and

问题描述：Say you have an array for which the ith element is the price of a given stock on day i. 给你一个数组，里边的第i个元素存储的是股票在第i天的价格 Design an algorithm to find the maximum profit. You may complete as many tra

问题描述：Say you have an array for which the ith element is the price of a given stock on day i. 给你一个数组，里边的第i个元素存储的是股票在第i天的价格 If you were only permitted to complete at most one transaction (ie, buy one a

问题描述：Say you have an array for which the ith element is the price of a given stock on day i. 给你一个数组，里边的第i个元素存储的是股票在第i天的价格 Design an algorithm to find the maximum profit. You may complete at most two

问题描述：Say you have an array for which the ith element is the price of a given stock on day i. 给你一个数组，里边的第i个元素存储的是股票在第i天的价格 Design an algorithm to find the maximum profit. You may complete at most k t

问题描述：给定一个数组，在此数组中寻找出3个数，使得3个数的和为0；并且3个数按非递减顺序输出。如输入：{-1,0,1,2,-1,-4};得到：-1 -1 2-1 0 1代码：#include <iostream>#include<vector>#include<algorithm>using namespace std;class Solution {public: vector

问题描述： Given a digit string, return all possible letter combinations that the number could represent.A mapping of digit to letters (just like on the telephone buttons) is given below. Input:Digit stri

问题描述：Given a linked list, remove the nth node from the end of list and return its head.For example,Given linked list: 1->2->3->4->5, and n = 2.After removing the second node from the end, the linked l

问题描述：有k个已经排好序的链表，将其合并为一个有序链表。代码：#include <iostream>#include<stdlib.h>#include<vector>using namespace std;struct ListNode { int val; ListNode *next; ListNode(int x) : val(x), next(NULL) {

问题描述： Given a linked list, reverse the nodes of a linked list k at a time and return its modified list.If the number of nodes is not a multiple of k then left-out nodes in the end should remain as it

问题描述：Divide two integers without using multiplication, division and mod operator.If it is overflow, return MAX_INT.也就是不用乘、除、取模运算实现两个数的除法。问题求解：因为不能用乘除法和取余运算，我们只能使用位运算和加减法。 任何一个整数可以表示成以2的幂为底的一组基的线性组合，即n

问题描述：You are given a string, s, and a list of words, words, that are all of the same length. Find all starting indices of substring(s) in s that is a concatenation of each word in words exactly once an

问题描述： Given a string containing just the characters ‘(’ and ‘)’, find the length of the longest valid (well-formed) parentheses substring.For “(()”, the longest valid parentheses substring is “()”, wh

问题描述：Given a binary tree, determine if it is a valid binary search tree (BST).Assume a BST is defined as follows:The left subtree of a node contains only nodes with keys less than the node’s key. The

问题描述： Two elements of a binary search tree (BST) are swapped by mistake.Recover the tree without changing its structure.Note: A solution using O(n) space is pretty straight forward. Could you devise

问题描述：Given a sorted array of integers, find the starting and ending position of a given target value.Your algorithm’s runtime complexity must be in the order of O(log n).If the target is not found in t

问题描述：Given two binary strings, return their sum (also a binary string).For example,a = "11"b = "1"Return "100".问题求解：二进制加法都是从最低位开始加（从右加到左）。所以对两个字符串要从最后一位开始加。每次相加之前先加上进位。class Solution {public: st

问题描述：Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number.An example is the root-to-leaf path 1->2->3 which represents the number 123.Find the total sum

问题描述：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.For example: Given the below binary tree and su

问题描述：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 depth of the two subtrees of every node never diffe

问题描述：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 array is non-empty and the majority element al

题目叙述： 在行和列都单增的矩阵里查找一个数是否存在 (Leetcode 74)题目求解： 代码实现（c++）class Solution {public: //利用vector<vector<int>>& matrix表示二维整型数组 bool searchMatrix(vector<vector<int>>& matrix, int target) {

问题描述：Given a binary tree, return all root-to-leaf paths.For example, given the following binary tree: 1 / \2 3 \ 5All root-to-leaf paths are:["1->2->5", "1->3"]问题求解：利用先序遍历，深度优先搜索方法求解。对此题而言

问题描述：Write an efficient algorithm that searches for a value in an m x n matrix. This matrix has the following properties:Integers in each row are sorted in ascending from left to right.Integers in eac

问题描述： 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 leaf node.方法一：深度优先搜索！/** * Definition for a b

问题描述： 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 leaf node.方法一：DFS/** * Definition for a binar

问题描述：Find the kth largest element in an unsorted array. Note that it is the kth largest element in the sorted order, not the kth distinct element.For example,Given [3,2,1,5,6,4] and k = 2, return 5.Not

问题描述：You are a product manager and currently leading a team to develop a new product. Unfortunately, the latest version of your product fails the quality check. Since each version is developed based on

问题描述：Implement int sqrt(int x).Compute and return the square root of x.问题求解：二分法。O（logN）class Solution {public: int mySqrt(int x) { long long low =1; long long high=x; lon

问题描述：Suppose a sorted array is rotated at some pivot unknown to you beforehand.(i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2).You are given a target value to search. If found in the array return its

问题描述：Follow up for “Search in Rotated Sorted Array”: What if duplicates are allowed?Would this affect the run-time complexity? How and why?Write a function to determine if a given target is in the arr

问题描述：Given a complete binary tree, count the number of nodes.In a complete binary tree every level, except possibly the last, is completely filled, and all nodes in the last level are as far left as po

问题描述：Suppose a sorted array is rotated at some pivot unknown to you beforehand.(i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2).Find the minimum element.You may assume no duplicate exists in the array.

问题描述：A peak element is an element that is greater than its neighbors.Given an input array where num[i] ≠ num[i+1], find a peak element and return its index.The array may contain multiple peaks, in that

问题描述：Given a binary search tree, write a function kthSmallest to find the kth smallest element in it.Note: You may assume k is always valid, 1 ≤ k ≤ BST’s total elements.再BST中找出第k小的元素。问题求解：中序遍历，只遍历k个

问题描述：Given a pattern and a string str, find if str follows the same pattern.Here follow means a full match, such that there is a bijection between a letter in pattern and a non-empty word in str.Exampl

问题描述：Given an unsorted array of integers, find the length of longest increasing subsequence.For example,Given [10, 9, 2, 5, 3, 7, 101, 18],The longest increasing subsequence is [2, 3, 7, 101], therefor

问题描述：Given an array of n positive integers and a positive integer s, find the minimal length of a subarray of which the sum ≥ s. If there isn’t one, return 0 instead.For example, given the array [2,3,1

问题描述：Given an integer array nums, find the sum of the elements between indices i and j (i ≤ j), inclusive.Example:Given nums = [-2, 0, 3, -5, 2, -1]sumRange(0, 2) -> 1sumRange(2, 5) -> -1sumRange(0,

问题描述：You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopping you from robbing each of them is that adjacent h