摘要：
Given two sparse matrices A and B, return the result of AB. You may assume that A's column number is equal to B's row number. Example: Solution: publi 阅读全文
摘要：
Given n balloons, indexed from 0 to n-1. Each balloon is painted with a number on it represented by array nums. You are asked to burst all the balloon 阅读全文
摘要：
Given a non negative integer number num. For every numbers i in the range 0 ≤ i ≤ num calculate the number of 1's in their binary representation and r 阅读全文