北叶青藤

2020年2月18日

摘要： Given an n-ary tree, return the level order traversal of its nodes' values. Nary-Tree input serialization is represented in their level order traversa 阅读全文

posted @ 2020-02-18 07:30 北叶青藤阅读(172) 评论(0) 推荐(0)

Counting Sort Implementation

摘要： Imagine you have an array like this (note that the array has duplicates, and includes 0 and k): a = [ 4, 64, 200, 42, 56, 22, 1, 64, 0, 161, 200, 0, 4 阅读全文

posted @ 2020-02-18 07:08 北叶青藤阅读(140) 评论(0) 推荐(0)

2020年2月8日

1216. Valid Palindrome III

摘要： Given a string s and an integer k, find out if the given string is a K-Palindrome or not. A string is K-Palindrome if it can be transformed into a pal 阅读全文

posted @ 2020-02-08 00:04 北叶青藤阅读(294) 评论(0) 推荐(0)

2020年2月7日

find the leftmost column that has number 1

摘要： Given a matrix, like this[[0, 0, 1, 1, 1][0, 1, 1, 1, 1][0, 0, 1, 1, 1][0, 0, 0, 0, 0]]each cell is either 1 or 0in each row, from left to right, when 阅读全文

posted @ 2020-02-07 11:18 北叶青藤阅读(178) 评论(0) 推荐(0)

1047. Remove All Adjacent Duplicates In String

摘要： Given a string S of lowercase letters, a duplicate removal consists of choosing two adjacent and equal letters, and removing them. We repeatedly make 阅读全文

posted @ 2020-02-07 08:18 北叶青藤阅读(148) 评论(0) 推荐(0)

129. Sum Root to Leaf Numbers

摘要： Given a binary tree containing digits from 0-9 only, each root-to-leaf path could represent a number. An example is the root-to-leaf path 1->2->3 whic 阅读全文

posted @ 2020-02-07 08:11 北叶青藤阅读(136) 评论(0) 推荐(0)

938. Range Sum of BST

摘要： Given the root node of a binary search tree, return the sum of values of all nodes with value between L and R (inclusive). The binary search tree is g 阅读全文

posted @ 2020-02-07 07:50 北叶青藤阅读(274) 评论(0) 推荐(0)

inorder of two BST

摘要：给两个bst，把它们的值按照从小到大打印。 1 public static void print2BSTInorder(TreeNode n1, TreeNode n2, List<Integer> result) { 2 Stack<TreeNode> stack1 = new Stack<>() 阅读全文

posted @ 2020-02-07 07:02 北叶青藤阅读(98) 评论(0) 推荐(0)

415. Add Strings

摘要： Given two non-negative integers num1 and num2 represented as string, return the sum of num1 and num2. Note: The length of both num1 and num2 is < 5100 阅读全文

posted @ 2020-02-07 06:38 北叶青藤阅读(173) 评论(0) 推荐(0)

byte swap

摘要： byte swap一个 32位数 0x12345678 --> 0x78563412先是用了俩高低位mask 两两交换，不满意。然后用了一个mask，每次取一个byte，移位异或ans。一共执行四次，还是不满意。提示说用两步，能不能先交换 LSB 和 MSB，写了一下，但还是想不出怎么写。。。正解：阅读全文

posted @ 2020-02-07 03:49 北叶青藤阅读(769) 评论(0) 推荐(0)

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