algorithm-python

Data structures and Algorithms in Python

By Patterns

Array

• Two Sum | Solution
• Best Time to Buy and Sell Stock | Solution
• Contains Duplicate | Solution
• Product of Array Except Self | Solution
• Maximum Subarray | Solution
• Maximum Product Subarray | Solution
• Find Minimum in Rotated Sorted Array
• Search in Rotated Sorted Array
• 3Sum
• Container With Most Water

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Binary

• Sum of Two Integers
• Number of 1 Bits
• Counting Bits
• Missing Number
• Reverse Bits

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Dynamic Programming

• Climbing Stairs
• Coin Change
• Longest Increasing Subsequence
• Longest Common Subsequence
• Word Break Problem
• Combination Sum
• House Robber
• House Robber II
• Decode Ways
• Unique Paths
• Jump Game

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Graph

• Clone Graph
• Course Schedule
• Pacific Atlantic Water Flow
• Number of Islands
• Longest Consecutive Sequence
• Alien Dictionary (Leetcode Premium)
• Graph Valid Tree (Leetcode Premium)
• Number of Connected Components in an Undirected Graph (Leetcode Premium)

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Interval

• Insert Interval
• Merge Intervals
• Non-overlapping Intervals
• Meeting Rooms (Leetcode Premium)
• Meeting Rooms II (Leetcode Premium)

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Linked List

• Reverse a Linked List
• Detect Cycle in a Linked List
• Merge Two Sorted Lists
• Merge K Sorted Lists
• Remove Nth Node From End Of List
• Reorder List

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Matrix

• Set Matrix Zeroes
• Spiral Matrix
• Rotate Image

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By Company

Meta: Top 100

Last updated: Mar 11, 2025

Index	Difficulty	Title	Frequency	Acceptance Rate	Status
1	Medium	Kth Largest Element in an Array	100.0%	67.4%	✅
2	Easy	Valid Word Abbreviation	97.1%	36.5%
3	Easy	Valid Palindrome II	95.5%	42.2%	✅
4	Medium	Minimum Remove to Make Valid Parentheses	94.6%	70.0%	✅
5	Easy	Merge Sorted Array	91.9%	51.9%	✅
6	Medium	Binary Tree Vertical Order Traversal	91.9%	56.2%
7	Medium	Random Pick with Weight	87.6%	48.0%
8	Medium	Lowest Common Ancestor of a Binary Tree	86.4%	65.1%
9	Medium	Basic Calculator II	85.1%	45.0%
10	Medium	Simplify Path	83.8%	45.9%
11	Medium	Dot Product of Two Sparse Vectors	82.4%	89.9%
12	Medium	Nested List Weight Sum	80.9%	85.0%
13	Medium	Buildings With an Ocean View	79.2%	80.3%
14	Medium	Minimum Add to Make Parentheses Valid	79.2%	74.7%
15	Medium	Shortest Path in Binary Matrix	79.2%	48.9%
16	Medium	"Pow(x	n)"%	7920.0%
17	Medium	Find Peak Element	77.5%	46.3%
18	Easy	Valid Palindrome	77.5%	49.7%
19	Easy	Diameter of Binary Tree	77.5%	62.4%
20	Easy	Range Sum of BST	75.6%	87.3%
21	Medium	Top K Frequent Elements	75.6%	63.9%
22	Medium	Remove Nth Node From End of List	73.6%	47.7%
23	Medium	Lowest Common Ancestor of a Binary Tree III	73.6%	81.6%
24	Medium	Sum Root to Leaf Numbers	71.4%	67.5%
25	Medium	Interval List Intersections	71.4%	72.3%
26	Medium	Find First and Last Position of Element in Sorted Array	71.4%	45.8%
27	Medium	LRU Cache	71.4%	44.1%
28	Hard	Minimum Window Substring	68.9%	44.4%
29	Medium	Merge Intervals	68.9%	48.5%
30	Hard	Merge k Sorted Lists	68.9%	55.3%
31	Medium	Clone Graph	66.2%	60.6%
32	Medium	Custom Sort String	66.2%	71.5%
33	Hard	Making A Large Island	66.2%	49.7%
34	Medium	K Closest Points to Origin	66.2%	67.4%
35	Easy	Moving Average from Data Stream	66.2%	79.4%
36	Hard	Trapping Rain Water	66.2%	63.9%
37	Easy	Two Sum	63.1%	54.7%
38	Hard	Valid Number	63.1%	20.9%
39	Easy	Palindrome Number	63.1%	58.3%
40	Easy	Closest Binary Search Tree Value	63.1%	50.4%
41	Medium	Binary Tree Right Side View	63.1%	64.9%
42	Easy	Kth Missing Positive Number	63.1%	61.5%
43	Medium	Next Permutation	63.1%	42.0%
44	Medium	Copy List with Random Pointer	59.5%	59.0%
45	Medium	Accounts Merge	59.5%	58.6%
46	Easy	Best Time to Buy and Sell Stock	59.5%	54.6%
47	Medium	Subarray Sum Equals K	59.5%	44.7%
48	Medium	Insert into a Sorted Circular Linked List	59.5%	37.4%
49	Easy	Add Strings	59.5%	51.7%
50	Easy	Recyclable and Low Fat Products	55.2%	89.4%
51	Hard	Vertical Order Traversal of a Binary Tree	55.2%	49.9%
52	Medium	Random Pick Index	55.2%	64.2%
53	Easy	Longest Common Prefix	55.2%	44.6%
54	Medium	Maximum Swap	55.2%	51.7%
55	Medium	Search in Rotated Sorted Array II	55.2%	38.4%
56	Medium	Course Schedule	55.2%	48.2%
57	Medium	Longest Palindromic Substring	55.2%	35.0%
58	Medium	Longest Substring Without Repeating Characters	50.1%	36.0%
59	Easy	Valid Parentheses	50.1%	41.6%
60	Easy	Remove Duplicates from Sorted Array	50.1%	58.9%
61	Medium	3Sum	50.1%	36.1%
62	Easy	Maximum Average Subarray I	50.1%	44.4%
63	Medium	Palindromic Substrings	50.1%	71.1%
64	Medium	Continuous Subarray Sum	50.1%	30.6%
65	Medium	Group Shifted Strings	50.1%	66.7%
66	Easy	Majority Element	50.1%	65.4%
67	Medium	Max Consecutive Ones III	50.1%	64.9%
68	Hard	Expression Add Operators	50.1%	40.8%
69	Medium	All Nodes Distance K in Binary Tree	50.1%	65.6%
70	Hard	Word Ladder	50.1%	41.4%
71	Easy	Contains Duplicate II	43.5%	47.6%
72	Medium	Max Area of Island	43.5%	72.8%
73	Easy	Roman to Integer	43.5%	63.7%
74	Easy	Remove All Adjacent Duplicates In String	43.5%	70.8%
75	Medium	Maximum Subarray	43.5%	51.6%
76	Hard	Binary Tree Maximum Path Sum	43.5%	40.7%
77	Hard	Valid Palindrome III	43.5%	49.2%
78	Medium	Check Completeness of a Binary Tree	43.5%	57.8%
79	Medium	Diagonal Traverse	43.5%	62.1%
80	Easy	Merge Strings Alternately	43.5%	81.5%
81	Medium	Add Two Numbers	43.5%	45.0%
82	Medium	Convert Binary Search Tree to Sorted Doubly Linked List	43.5%	65.3%
83	Easy	Create Hello World Function	43.5%	81.8%
84	Medium	Word Break	43.5%	47.7%
85	Medium	Reverse Integer	34.3%	29.7%
86	Medium	Exclusive Time of Functions	34.3%	63.7%
87	Easy	Next Greater Element I	34.3%	73.7%
88	Medium	Walls and Gates	34.3%	62.3%
89	Medium	Find Largest Value in Each Tree Row	34.3%	66.4%
90	Easy	Find the Index of the First Occurrence in a String	34.3%	44.2%
91	Medium	Zigzag Conversion	34.3%	50.3%
92	Easy	Remove Element	34.3%	59.1%
93	Easy	Toeplitz Matrix	34.3%	69.4%
94	Medium	Rotate Image	34.3%	76.8%
95	Easy	Missing Ranges	34.3%	34.8%
96	Medium	Shortest Path in a Hidden Grid	34.3%	43.2%
97	Medium	Subsets	34.3%	79.9%
98	Hard	Longest Increasing Path in a Matrix	34.3%	54.7%
99	Medium	Boundary of Binary Tree	34.3%	46.6%
100	Medium	Count Ways To Build Good Strings	34.3%	59.4%

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References :

1. https://www.coursera.org/learn/algorithms-part1/
2. https://www.coursera.org/learn/algorithms-part2/
3. Data Structures and Algorithms in Python Paperback – 2016 | Michael T. Goodrich (Author), Roberto Tamassia (Author), Michael H. Goldwasser (Author)
4. Introduction to Algorithms, 3Ed. (International Edition) (The MIT Press) Paperback – 20 Aug 2009 | T Cormen (Author), C Leiserson (Author), R Rivest (Author), C Stein (Author)