纽约在职刷题

399. Evaluate Division. Graph building and bfs.

75. Sort Colors. Two pointers, three indices Dutch national flag / partition sort.

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309. Best Time to Buy and Sell Stock with Cool Down. Dynamic programming as a state transition machine. State/ subproblems, and transition matrix.

补充内容 (2019-9-6 01:58):
309. Best Time to Buy and Sell Stock with Cool Down. Dynamic programming as a state transition machine. State/ subproblems, and transition matrix.

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300. Longest Increasing Subsequence. Binary Search with Dynamic Programming

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58. Length of Last Word. 竟然没写出pythonic的写法。用linear scan reverse扫了一遍。

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66. Plus One. 类似58。这些早期Easy收获这么多dislikes

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69. Sqrt(x). Binary Search, Newton's method, bit manipulation.

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83. Remove Duplicates from Sorted List. 怎么移除Linked List的Node

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100. Same Tree. Binary tree recursion.

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107. Binary Tree Level Order Traversal II. 跟102一模一样的题。一个是easy，一个是medium. LeetCode看来也是有点混乱。BFS on tree.

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110. Balanced Binary Tree. Recursive. 用-1记录深度函数得出的一个不平衡的状态

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112. Path Sum. Binary Tree DFS. 注意base case的写法。

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119. Pascal's Triangle II. DP。用list comprehension可以更Pythonic.

157. Read N Characters Given Read4.

168. Excel Sheet Column Title. 减去1的trick来对付从1开始而不是从零开始。或者给residual分类处理。

170. Two Sum III Data Structure Design.

172. Factorial Trail Zero. Quant的脑筋急转弯问题变成编程题。

14. Longest Commom Prefix. Vertical Scan加上一个pre sort based on Len.





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202. Happy Number. 有时候不需要过度优化。存int在set里面。

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819. Most Common Word. String上的一些library function操作。

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509. Fibonacci Number. Golden ratio formula.

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415. Add Strings. 不用int，在单一digit上用ord减去ord('0')

楼主想去哪里工作？我在fintech上班刷题想转纯tech。。。

goatKnighttt 发表于 2019-9-7 11:20
楼主想去哪里工作？我在fintech上班刷题想转纯tech。。。

楼主看来看去觉得现在去TECH最合适自己的情况了

1165. Single Row Keyboard. Dict

709. To Lower Case. String Library

977. Squares of a Sorted Array.  Smart linear scan.

852. Peak Index in a Mountain Array.

1108. Defanging an IP address. 好多string的基本操作

965. Univalued Binary Tree

346. Moving Average from Data Stream

359. Logger Rate Limiter.

1047. Remove All Adjacent Duplicates In String. Stack

1170. Compare Strings by Frequency of the Smallest Character. String上的min, count等等library functions.

243. Shortest Word Distance.

252. Meeting Rooms. Sort. operator.itemgetter()

268. Missing Number. XOR. X^X = 0, X^0 = X

350. Intersection of Two Arrays II. Sort or dict/ counter based solutions.

836. Rectangle Overlap. Variation of Interval Overlap

551. Student Attendance Record I. Linear Scan vs using library

231. Power of Two. x & (x-1) == 0 or x ^ (-x) == x if x != 0

849. Maximize Distance to Closest Person.







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724. Find Pivot Index. Partial Sum.

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205. Isomorphic Strings. One to One and Onto

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941. Valid Mountain Array

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374. Guess Number Higher or Lower. Binary Search

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299. Bulls and Cows. Hash Table

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734. Sentence Similarity. defaultdict(set), zip

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747. Largest Number At Least Twice of Others. Largest and second largest

162. Find Peak Element. Binary search on unsorted array for local maximum.

208. Implement Trie (Prefix Tree). Implement TrieNode first. Binary tree with more childrens. dict or array for children nodes

228. Summary Ranges. 貌似是可以binary search，流行AC解法都是线性解。

230. Kth Smallest Element in a BST. BST inorder traverse

247. Strobogrammatic Number II.

249. Group Shifted Strings. circular modula %


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251. Flatten 2D Vector.

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59. 3Sum Smaller. Two pointers on sorted array

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979. Distribute Coins in Binary Tree. DFS on bt

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951. Flip Equivalent Binary Trees. DFS on BT

1110. Delete Node and Return Forest. parameter downstream and return upstream

1087. Brace expansion.

1055. Shortest way to Form String

117. Populating Next Right Pointers in Each Node II


补充内容 (2019-9-13 03:25):
334. Increasing Triplet Subsequence. 跟longest increasing subsequence思路有点类似。

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896. Monotonic Array.

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1099. Two Sum Less Than K

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997. Find the Town Judge

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994. Rotting Oranges. BFS on Grid Graph

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256. Paint House. Dynamic programming as Easy....

987. Vertical Order Traversal of a Binary Tree. 应该是BFS最优，可以省去Y的排序。虽然简单粗暴也可以AC。

222. Count Complete Tree Nodes. 在最后一行做Binary Search找插入点。每次evaluation by index的思路也是binary search类似