题目：Given two words (beginWord and endWord), and a dictionary's word list, find all shortest transformation sequence(s) from beginWord to endWord, such that:

Matrix中的path问题：62.Unique Paths63.Unique Paths II这两题是典型的dp问题，要求一共有多少种方案。分析状态f(i, j)是走到(i, j)总共的路径。它可以由前面两个状态得到，即f(i, j)=f(i - 1, j) + f(i, j - 1)。最后注意边界值即可。变形是有设obstacle, 那么遇到...

题目：Given a data stream input of non-negative integers a1, a2, ..., an, ..., summarize the numbers seen so far as a list of disjoint intervals.

题目：Given an array nums containing n + 1 integers where each integer is between 1 and n (inclusive), prove that at least one duplicate number must exist. Assume that there is only one duplicate number, find the duplicate one.

题目：An image is represented by a binary matrix with 0 as a white pixel and 1 as a black pixel. The black pixels are connected, i.e., there is only one black region. Pixels are connected horizontally and vertically. Given the location (x, y) of o...

题目：Given an array of integers, find out whether there are two distinct indices i and j in the array such that the difference between nums[i] and nums[j] is at most t and the difference between i and j is at most k.

题目：Given two words (beginWord and endWord), and a dictionary's word list, find the length of shortest transformation sequence from beginWord to endWord, such that:

For example,path = "/home/", => "/home"path = "/a/./b/../../c/", => "/c"click to show corner cases.

题目：Given a 2D board and a list of words from the dictionary, find all words in the board.

题目：Additive number is a string whose digits can form additive sequence.

题目：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.

最近正在面试uber，uber以频繁考察系统设计而著名，系统设计是一个没有标准答案的open-end问题，所以关键在于对于特定问题的设计选择,俗称trade-off，这个思维平时无处锻炼，故开启此文，记录学习和理解的过程。 本文全部题目和分析来自《Elements Of Programming In...

题目：Given a linked list, return the node where the cycle begins. If there is no cycle, return null.

题目：Given n non-negative integers representing an elevation map where the width of each bar is 1, compute how much water it is able to trap after raining.

题目：Suppose you are at a party with n people (labeled from 0 to n - 1) and among them, there may exist one celebrity. The definition of a celebrity is that all the other n - 1 people know him/her but he/she does not know any of them.

问题：According to the Wikipedia's article: "The Game of Life, also known simply as Life, is a cellular automaton devised by the British mathematician John Horton Conway in 1970."

246.Strobogrammatic NumberI题目：A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down).

Given a sorted array of integers nums and integer values a, b and c. Apply a function of the form f(x) = ax2 + bx + c to each element x in the array. The returned array must be in sorted order. Expected time complexity: O(n) Example:nums = [-4, -2...

题目：Given a sorted array of integers nums and integer values a, b and c. Apply a function of the form f(x) = ax2 + bx + c to each element x in the array.

题目：Given an array containing n distinct numbers taken from 0, 1, 2, ..., n, find the one that is missing from the array.