摘要：
Determine the number of bits required to flip if you want to convert integer n to integer m. Example Given n = 31 (11111), m = 14 (01110), return 2. N 阅读全文
摘要：
Flatten a binary tree to a fake "linked list" in pre-order traversal. Here we use the right pointer in TreeNode as the nextpointer in ListNode. Exampl 阅读全文
摘要：
For a given sorted array (ascending order) and atarget number, find the first index of this number inO(log n) time complexity. If the target number do 阅读全文
摘要：
Implement an algorithm to delete a node in the middle of a singly linked list, given only access to that node. Example Given 1->2->3->4, and node 3. r 阅读全文
摘要：
The count-and-say sequence is the sequence of integers beginning as follows: 1, 11, 21, 1211, 111221, ... 1 is read off as "one 1" or 11. 11 is read o 阅读全文
摘要：
Count how many 1 in binary representation of a 32-bit integer. Example Given 32, return 1 Given 5, return 2 Given 1023, return 9 Challenge If the inte 阅读全文
摘要：
Cosine similarity is a measure of similarity between two vectors of an inner product space that measures the cosine of the angle between them. The cos 阅读全文
摘要：
Given a sorted (increasing order) array, Convert it to create a binary tree with minimal height. Example Given [1,2,3,4,5,6,7], return 4 / \ 2 6 / \ / 阅读全文
摘要：
Compare two strings A and B, determine whether A contains all of the characters in B. The characters in string A and B are all Upper Case letters. Exa 阅读全文