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MEAN-stack Project

MEAN全栈项目技术笔记

What is Angular? (for front-end) a Client-Side (Browser) Framework which allows you to build Single-Page-Applications render UI with dynamic data handle user input communicate with backend s...

Posted by Eryn on November 30, 2019

DP Problems

dp题目总结

Memonization Search & Dynamic Programming Word Break III Triangle Word Break Word Break II Wildcard Matching Regular Expression Matching 4 key points DP and coordinate DP ### Unique Paths II...

Posted by Eryn on November 26, 2019

Default Interview Problems

常见技术面试题目总结

longest palindrome 创建array存放所有的char，所以注意标注array的大小int[] count = new int[256] 统计String中每一个char出现的次数for (char c : s.toCharArray()) count[c]++; 偶数可以全用上total += even_number 奇数中的偶数次可以用上total +...

Posted by Eryn on November 26, 2019

Bianry Tree and Divide & Conquer Problems

二叉树，分治法和题目总结

Binary Tree Divide & Conquer ### Closest Binary Search Tree Value Vertical Order Traversal of a Binary Tree Minimum Subtree Binary Tree Paths Flatten Binary Tree to Linked List Balanced Binar...

Posted by Eryn on November 26, 2019

Hash & Heap Problems

哈希，堆结构和题目总结

Hash & Heap Moving Average from Data Stream average两个重要部分，sum和数量，average = sum / count window size是给的，也就是用于计算average的count moving average 用到sum，应该想到维护一个accum sum array，存前i位的sum，但是这个arra...

Posted by Eryn on November 24, 2019

DFS Problems

深度优先搜索和题目总结

DFS BFS & DFS 区别 BFS一般是最近距离，最少步数的问题 DFS一般是最远距离，最多步，最深 Split String Letter Combinations of a Phone Number 因为given number的形式是String，那么String数字（‘0’，‘1’…）有什么特殊的操作方法？在不转换type的情况下输入我们Strin...

Posted by Eryn on November 24, 2019

BFS Problems

宽度优先搜索和题目总结

BFS why prefer start + (end - start) / 2 than (start + end) / 2？ 当start和end都是很大的integer时，加在一起会overflow。前者不会，因为只要end >= start，前者就不会overflow。（而我们binary search的while loop条件就是start + 1 < end，所以...

Posted by Eryn on November 24, 2019

Binary Search Problems

二分搜索法和题目总结

Binary Search Last Position of Target leetcode 34 Find first and last position of element in sorted array find first 一直往左靠，向头部靠，当nums[mid]==target时right = mid find last 一直往右靠，末尾靠，当nums[mid]...

Posted by Eryn on November 23, 2019

'Serialize' in Java

理解Java中的序列化和反序列化

Serialize and Deserialize encode and decode Serialize and Deserialize Binary Tree Serialize 全局变量String result = "" & int id = 0 只要root不是null，每一次call serialwork就id++，然后把值赋给nowId，即当前树的id ...

Posted by Eryn on November 19, 2019

'Binary Tree' in Java

理解Java中的二叉树

Binary Tree前中后序遍历要弄清楚（有template） 可以看recursion整理pre/post/in-order的思路，但是面试会考iteration In-order void inOrderTraversal(TreeNode node) { if (node != null) { inOrderTraversal(node.left); ...

Posted by Eryn on November 17, 2019

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Java Java Basics Coding Interview Leetcode Data Structure Binary Tree Algorithm DFS
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