摘要：
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? 阅读全文
摘要：
Given a linked list, determine if it has a cycle in it. Follow up: Can you solve it without using extra space? tags提示：two pointers 采用“快慢双指针”的方法来判断： 每次 阅读全文
摘要：
Say you have an array for which the ith element is the price of a given stock on day i.Design an algorithm to find the maximum profit. You may complet 阅读全文
摘要：
Say you have an array for which the ith element is the price of a given stock on day i. Design an algorithm to find the maximum profit. You may comple 阅读全文
摘要：
Say you have an array for which the ith element is the price of a given stock on day i. If you were only permitted to complete at most one transaction 阅读全文
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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 阅读全文
摘要：
Given an array of integers, every element appears twice except for one. Find that single one. Your algorithm should have a linear runtime complexity. 阅读全文
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Given inorder and postorder traversal of a tree, construct the binary tree. You may assume that duplicates do not exist in the tree. 阅读全文
摘要：
Given preorder and inorder traversal of a tree, construct the binary tree. You may assume that duplicates do not exist in the tree. 阅读全文
摘要：
Given a binary tree, return the zigzag level order traversal of its nodes' values. (ie, from left to right, then right to left for the next level and 阅读全文