A group of friends went on holiday and sometimes lent each other money. ...
Design a Phone Directory which supports the following operations: get: P...
Given an encoded string, return it's decoded string. The encoding rule i...
Suppose an array sorted in ascending order is rotated at some pivot unkn...
A strobogrammatic number is a number that looks the same when rotated 18...
Given a binary tree, return the level order traversal of its nodes' valu...
Given a string, sort it in decreasing order based on the frequency of ch...
Given a string s and a string t, check if s is subsequence of t. You may...
这本书是作者在长达24册耗时50年时间完成《西方文明史》,浓缩后的感悟和精华,字字珠玑,让人回味很久。也立下了一个小小的心愿,有机会一定要啃完这...