apanda009

摘要： 就是一棵任意形状的树，给你一个数k，让你把这棵数变成每个节点只有k或者0个孩子的结构，之前某节点孩子不可以变成该节点的祖先，但是可以是兄弟由于第一题扣细节逻辑花了40分钟（主要是我一开始没有理解面试官的困惑，然后一步一步的解释来着），第二题就说了个思路（我的想法就是层序遍历然后把对应是一层的节点放到 阅读全文

摘要： Solution 1: Reservior sampling: (wiki introduction) Reservoir sampling is a family of randomized algorithms for randomly choosing a sample of k items 阅读全文

摘要： Strobogrammatic Number II give us all the strings with length n, then we can call it to get strings with length between low.length() and high.length() 阅读全文

摘要： 参考http://segmentfault.com/a/1190000003787462 找出所有的可能，必然是深度优先搜索。但是每轮搜索如何建立临时的字符串呢？因为数是“对称”的，我们插入一个字母就知道对应位置的另一个字母是什么，所以我们可以从中间插入来建立这个临时的字符串。这样每次从中间插入两个 阅读全文

摘要： A strobogrammatic number is a number that looks the same when rotated 180 degrees (looked at upside down). Write a function to determine if a number is strobogrammatic. The number is represented as ... 阅读全文

摘要： Since n may be a large number compared to the length of list. So we need to know the length of linked list.After that, move the list after the (l-n%l 阅读全文

摘要： Given two strings A and B, find the minimum number of times A has to be repeated such that B is a substring of it. If no such solution, return -1. For 阅读全文

摘要： Given a data stream input of non-negative integers a1, a2, ..., an, ..., summarize the numbers seen so far as a list of disjoint intervals. For exampl 阅读全文

摘要： How do we solve problem like this if we were given a normal tree? Yes, traverse it, keep a root to leaf running sum. If we see a leaf node (node.left 阅读全文

摘要： The general solution would be to check each char in turn and report the first char that makes the string a non number. There are some exceptions to wa 阅读全文