摘要：
Given a singly linked list, return a random node's value from the linked list. Each node must have the same probability of being chosen. Follow up:Wha 阅读全文
摘要：
Shuffle a set of numbers without duplicates. Example: 给一个没有重复数字的数组，实现重置和洗牌的功能。 解法：遍历数组每个位置，每次都随机生成一个坐标位置，然后交换当前位置和随机位置的数字，这样如果数组有n个数字，那么也随机交换了n组位置，从而达 阅读全文
摘要：
Given a robot cleaner in a room modeled as a grid. Each cell in the grid can be empty or blocked. The robot cleaner with 4 given APIs can move forward 阅读全文
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A group of friends went on holiday and sometimes lent each other money. For example, Alice paid for Bill's lunch for 10.ThenlaterChrisgaveAlice10.Then 阅读全文
摘要：
Given inorder and postorder traversal of a tree, construct the binary tree. Note:You may assume that duplicates do not exist in the tree. For example, 阅读全文
摘要：
Given preorder and inorder traversal of a tree, construct the binary tree. Note:You may assume that duplicates do not exist in the tree. For example, 阅读全文