摘要：
Given an unsorted array nums, reorder it in-place such that nums[0] <= nums[1] >= nums[2] <= nums[3].... For example, given nums = [3, 5, 2, 1, 6, 4], 阅读全文
摘要：
Given a singly linked list, group all odd nodes together followed by the even nodes. Please note here we are talking about the node number and not the 阅读全文
摘要：
One way to serialize a binary tree is to use pre-order traversal. When we encounter a non-null node, we record the node's value. If it is a null node, 阅读全文