Tim's Blog

Question: Sort a linked list using insertion sort. Solution: /** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x),

/** * Definition for singly-linked list. * struct ListNode { * int val; * ListNode *next; * ListNode(int x) : val(x), next(NULL) {} * }; */ class Solution { public: ListNode *de

Question: Given n points on a 2D plane, find the maximum number of points that lie on the same straight line. 分析： 任意一条直线都可以表述为 y = ax + b 假设，有两个点(x1,y1), (x2,y2)，如果他们都在这条直线上则有

Question: Given a linked list, determine if it has a cycle in it. Follow up: Can you solve it without using extra space? Answer

Question: 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:

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: What constitutes

Question: 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},

Question: 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: R

Question: 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

Question: 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) of

Question: Implement strStr(). Returns a pointer to the first occurrence of needle in haystack, or null if needle is not part of haystack. Solution (C++): class Solution { public: char *s

题目来源：Leetcode（www.leetcode.com） Question： Determine whether an integer is a palindrome. Do this without extra space. Solution： First, the problem statement did not specify if negative in

Question: Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses. For example, given n = 3, a solution set is: "((()))", "(()())", "(())()", "(

Question:  Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order. For example, Given the following matrix: [ [ 1, 2, 3 ], [ 4, 5, 6 ], [ 7, 8

Given a list, rotate the list to the right by k places, where k is non-negative. For example: Given 1->2->3->4->5->NULL and k = 2, return 4->5->1->2->3->NULL. 解法：游标指针从头节点向后移动，当指向尾节点时，得到链表长度len

Question: 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",