摘要： You need to construct a string consists of parenthesis and integers from a binary tree with the preorder traversing way. The null node needs to be rep 阅读全文

摘要： Given a list of directory info including directory path, and all the files with contents in this directory, you need to find out all the groups of dup 阅读全文

摘要： A sequence of number is called arithmetic if it consists of at least three elements and if the difference between any two consecutive elements is the 阅读全文

摘要： Given a sorted array consisting of only integers where every element appears twice except for one element which appears once. Find this single element 阅读全文

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

摘要： Given a binary tree, find the leftmost value in the last row of the tree. Example 1: Example 2: 阅读全文

摘要： Given a string, your task is to count how many palindromic substrings in this string. The substrings with different start indexes or end indexes are c 阅读全文

摘要： Given two strings representing two complex numbers. You need to return a string representing their multiplication. Note i2 = -1 according to the defin 阅读全文

摘要： Given a non negative integer number num. For every numbers i in the range 0 ≤ i ≤ num calculate the number of 1's in their binary representation and r 阅读全文

摘要： Reverse bits of a given 32 bits unsigned integer. For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), retur 阅读全文