北叶青藤

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). Note: Note that in some 阅读全文

摘要： In an N by N square grid, each cell is either empty (0) or blocked (1). A clear path from top-left to bottom-right has length k if and only if it is c 阅读全文

摘要： Given the root of a binary tree, find the maximum value V for which there exists different nodes A and B where V = |A.val - B.val| and A is an ancesto 阅读全文

摘要： In a given array nums of positive integers, find three non-overlapping subarrays with maximum sum. Each subarray will be of size k, and we want to max 阅读全文

摘要： Given an array A of non-negative integers, return the maximum sum of elements in two non-overlapping (contiguous) subarrays, which have lengths L and  阅读全文

摘要： Let's call an array A a mountain if the following properties hold: A.length >= 3 There exists some 0 < i < A.length - 1 such that A[0] < A[1] < ... A[ 阅读全文

摘要： There are N students in a class. Some of them are friends, while some are not. Their friendship is transitive in nature. For example, if A is a direct 阅读全文

摘要： Given a rooted binary tree, return the lowest common ancestor of its deepest leaves. Recall that: The node of a binary tree is a leaf if and only if i 阅读全文

摘要： Given a circular array (the next element of the last element is the first element of the array), print the Next Greater Number for every element. The 阅读全文

摘要： You are given two arrays (without duplicates) nums1 and nums2 where nums1’s elements are subset of nums2. Find all the next greater numbers for nums1' 阅读全文