摘要： Given a 2d grid map of '1's (land) and '0's (water), count the number of islands. An island is surrounded by water and is formed by connecting adjacen... 阅读全文

摘要： Given a binary tree, imagine yourself standing on the right side of it, return the values of the nodes you can see ordered from top to bottom.For exam... 阅读全文

摘要： You are a professional robber planning to rob houses along a street. Each house has a certain amount of money stashed, the only constraint stopping yo... 阅读全文

摘要： Write a function that takes an unsigned integer and returns the number of ’1' bits it has (also known as the Hamming weight).For example, the 32-bit i... 阅读全文

摘要： Reverse bits of a given 32 bits unsigned integer.For example, given input 43261596 (represented in binary as 00000010100101000001111010011100), return 阅读全文

摘要： Rotate an array of n elements to the right by k steps.For example, with n = 7 and k = 3, the array [1,2,3,4,5,6,7] is rotated to [5,6,7,1,2,3,4].Note:... 阅读全文

摘要： Say you have an array for which the ith element is the price of a given stock on day i.Design an algorithm to find the maximum profit. You may complet... 阅读全文