摘要：
查找等差数列中的缺失项. e.g.Input: arr[] = {2, 4, 8, 10, 12, 14} Output: 6 Input: arr[] = {1, 6, 11, 16, 21, 31}; Output: 26. 采用binary search. 若是arr[mid] - arr[l 阅读全文
摘要：
原题链接在这里：https://leetcode.com/problems/binary-tree-vertical-order-traversal/ 题目： Given a binary tree, return the vertical order traversal of its nodes' 阅读全文