limwz的专栏

问题描述如下： Design a stack that supports push, pop, top, and retrieving the minimum element in constant time. push(x) -- Push element x onto stack.pop() -- Removes the element on top of the stack.

问题描述如下： Given a singly linked list L: L0→L1→…→Ln-1→Ln, reorder it to: L0→Ln→L1→Ln-1→L2→Ln-2→… You must do this in-place without altering the nodes' values. For example, Given {1,2,3,4}, r

问题描述如下： Given a linked list, return the node where the cycle begins. If there is no cycle, return null. Follow up: Can you solve it without using extra space? 问题链接 cpp代码如下： class Solution

问题描述如下： A linked list is given such that each node contains an additional random pointer which could point to any node in the list or null. Return a deep copy of the list. 问题链接 cpp代码如下： cla

问题描述如下： Given a string s and a dictionary of words dict, add spaces in s to construct a sentence where each word is a valid dictionary word. Return all such possible sentences. For example,

问题描述如下： Given a string s and a dictionary of words dict, determine if s can be segmented into a space-separated sequence of one or more dictionary words. For example, given s = "leetcode", d

Given an array of integers, every element appears twice except for one. Find that single one. Note: Your algorithm should have a linear runtime complexity. Could you implement it without using ext

There are N gas stations along a circular route, where the amount of gas at station i is gas[i]. You have a car with an unlimited gas tank and it costs cost[i] of gas to travel from station i to

Clone an undirected graph. Each node in the graph contains a label and a list of its neighbors. OJ's undirected graph serialization: Nodes are labeled uniquely. We use # as a separator for each

问题描述如下： Given an array of integers, every element appears three times except for one. Find that single one. Note: Your algorithm should have a linear runtime complexity. Could you implement i

There are N children standing in a line. Each child is assigned a rating value. You are giving candies to these children subjected to the following requirements: Each child must have at least on

问题描述如下： Design and implement a data structure for Least Recently Used (LRU) cache. It should support the following operations: get and set. get(key) - Get the value (will always be positive) o

问题描述如下： Given a linked list, determine if it has a cycle in it. Follow up: Can you solve it without using extra space? 问题链接 cpp代码如下： class Solution { public: bool hasCycle(ListNode *he

问题描述如下： Write a program to find the node at which the intersection of two singly linked lists begins. For example, the following two linked lists: A: a1 → a2 ↘

问题描述如下： Follow up for "Find Minimum in Rotated Sorted Array": What if duplicates are allowed? Would this affect the run-time complexity? How and why? Suppose a sorted array is rotated at

问题描述如下： 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 duplica

问题描述如下： Given n points on a 2D plane, find the maximum number of points that lie on the same straight line. 问题链接 cpp代码如下： class Solution { public: int maxPoints(vector &points) { i

问题描述如下： Given an input string, reverse the string word by word. For example, Given s = "the sky is blue", return "blue is sky the". click to show clarification. Clarification: Wha

问题描述如下： Evaluate the value of an arithmetic expression in Reverse Polish Notation. Valid operators are +, -, *, /. Each operand may be an integer or another expression. Some examples:

问题描述如下： Sort a linked list in O(n log n) time using constant space complexity. 问题链接 问题链接 问题链接 问题链接 问题链接 问题链接 问题链接 问题链接 问题链接 问题链接 问题链接 问题链接 问题链接 cpp代码如下： class Solution { public: ListNode

问题描述如下： Sort a linked list using insertion sort. 问题链接 cpp代码如下： class Solution { public: ListNode *insertionSortList(ListNode *head) { if(head==NULL||head->next==NULL)return head;

问题描述如下： Given a binary tree, return the postorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [3,2,1]. Note: Re

问题描述如下： Given a binary tree, return the preorder traversal of its nodes' values. For example: Given binary tree {1,#,2,3}, 1 \ 2 / 3 return [1,2,3]. Note: Rec