Algomuscle

Train Your Algorithm Muscles Every Day!

Contents

Daily Progress Log

Day 1 - Arrays Part 1

Question# Title Solution Difficulty Topics Notes
704 Binary Search right-open, right-close Easy Arrays  
27 Remove Element Brute Force, Two Pointer) Easy Arrays Two pointer and brute force

Day 2 - Arrays Part 2

Question# Title Solution Difficulty Topics Notes
977 Squares of a Sorted Array Python Easy Two pointer Opposite Directions
209 Minimum Size Subarray Sum Python Medium Sliding window  
59 Spiral Matrix II Python Medium Simulation& Arrays Use four directions instead of multiple for loops
23 Merge k Sorted Lists Python Hard Linked List & min-heap Need review heap
88 Merge Sorted Array Python Easy Two Pointer Need review

Day 3 - LinkedList Part 1

Question# Title Solution Difficulty Topics Notes
203 Remove Linked List Elements Python Easy Linked List Review the properties of Linked List, implement iteration
707 Design Linked List Python Medium Linked List Great example for learning about the inner workings of Linked List
206 Reverse Linked List Python Easy Linked List review reversing a linked list

Day 4 - LinkedList Part 2

Question# Title Solution Difficulty Topics Complexity Nodes
24 Swap nodes in pairs Stack - Python, Recursion - Python Medium Linked List Stack: T:O(n),S:O(1) Recursion: T:O(n),S:O(n)  
19 Remove Nth Node From End of List Two Pointer - Python Medium Linked List, Two Pointer Two Pointer: T:O(n), S:O(1)  
160 Intersection of Two Linked Lists Two Pointer - Python, Hashtable - Python Easy Linked List, Two Pointer, Hash Table Two Pointer: T: O(n) S:O(1), Hashtable: T:O(n), S: O(n)  
142 Linked List Cycle II HashTable - Python, Two Pointer - Python Medium Linked List, Hash Table, Two Pointer Hash Table: T: O(n), S: O(n), Two Pointer: T:O(n),S:O(1)  

Day 6 - HashMap-Part1

Question# Title Solution Difficulty Topics Complexity Nodes
242 Valid Anagram Counter-Space Save, Counter-easy coding Easy Hash Table, String Space Save: T:O(n),S:O(1), Easy Coding: T:O(n),S:O(n)  
349 Intersection of Two Array Set- Hash Table, dictionary-Hash Table Easy Hash Table, Array set: T:O(n+m), S:(n+m), dictionary: T:O(n+m), S: O(n)  
202 Happy Number Set - Hash Table, Two Pointer Easy Hash Table, Two Pointer Set: T: O(d) where d is the numberof digits in n, S:O(k) where k is the number of unique digits in set(), Two Pointer: S: O(logn) where n is the size of the input value, T: O(1)  
1 Two Sum Dictionary Easy Hash Table, Array Hash Table: T: O(n), S: O(n)  
34 Find First and Last Position of Element in Sorted Array bisect - Binary Search, regular - Binary Search Medium Hash Table, Array bisect: T: O(logn), S: O(1), Regular binary Search: O(n) where n is the number of elements in the array, S: O(1)  

Day 7 - HashMap-Part2

Question# Title Solution Difficulty Topics Complexity Nodes
454 4Sum II 1. Concise Counter, 2. Dictionary, 3. Regular Counter Medium Hash Table, Array Concise Counter: T:O(n^2),S:O(n^2)  
383 Ransom Note 1. Concise Counter, 2. for + count, 3. count + all, 4. Dictionary, 5. Counter + sum Easy Hash Table, String, Counting Counter: T/S: O(r + m) where r is the length of ransomNote and m is the leght of magazine  
15 3Sum 1. Two Pointer Medium Array, Two Pointers, Sorting T: O(n^2), S: O(n^2)  
18 4Sum 1. Two Pointer Medium Hash Table, Array, Sorting T: O(n^3), S: O(m) where m is the number of unique quadruplets that sums up to the target  

Day 8 - String Part 1

Question# Title Solution Difficulty Topics Nodes
344 Reverse String Python Easy String, Two Pointers  
541 Reverse StringII Python Easy Two Pointer, String  
54 Kama-Replace numbers Python Easy String  
151 Reverse Words in a String Python Medium String, Two Pointer  
55 Kama-Right Rotate a String Python Easy String  

Day 9 - String Part 2

Question# Title Solution Difficulty Topics Nodes
28 Find the Index of the First Occurrence in a String Python Easy String, Two Pointers review kmp at 1/4/2024
459 Repeated Substring Pattern Python Easy Two Pointer, String has reviewed kmp at 1/4/2024
268 Smallest Missing Integer Python Easy Array, Hash Table set(), in-place Hashing

Day 10 - Stack and Queue Part 1

Question# Title Solution Difficulty Topics Nodes
232 Implement Queue using Stacks Python Easy Stack, Queue  
225 Implement Stack using Queues Python Easy Stack, Queue  

Day 11 - Stack and Queue Part 2

Question# Title Solution Difficulty Topics Nodes
20 Valid Parentheses Python Easy Stack, Dictionary  
1047 Remove All Adjacent Duplicates In String Python Easy Stack, Dictionary  
150 Valid Parentheses Python Medium Stack, Dictionary  

Day 13 - Stack and Queue Part 3

Question# Title Solution Difficulty Topics Nodes
239 Sliding Window Maximu Python Hard Monotonic Queue, Heap, Priority Queue  
347 Top K Frequent Elements Python Medium Min Heap, Priority Queue, Hash Table  
692 Top K Frequent Words Python Medium Min Heap, Hash Table, Sorting Need Review again

Day 14 - Binary Tree Part 1

Question# Title Solution Difficulty Topics Nodes
144 Binary Tree Preorder Traversal Python Easy Binary Tree  
145 Binary Tree Postorder Traversal Python Easy Binary Tree  
94 Binary Tree Inorder Traversal Python Easy Binary Tree  

Day 15 - Binary Tree Part 2

Question# Title Solution Difficulty Topics Nodes
102 Binary Tree Level Order Traversal Python Medium Binary Tree  
107 Binary Tree Level Order Traversal II Python Medium Binary Tree  
199 Binary Tree Right Side View Python Medium Binary Tree  
637 Average of Levels in Binary Tree Python Easy Binary Tree  
429 N-ary Tree Level Order Traversal Python Medium N-ary Tree  
515 Find Largest Value in Each Tree Row Python Medium Binary Tree  
116 Populating Next Right Pointers in Each Node Python Medium Binary Tree  
117 Populating Next Right Pointers in Each Node II Python Medium Binary Tree  
104 Maximum Depth of Binary Tree Python Easy Binary Tree  
111 Minimum Depth of Binary Tree Python Easy Binary Tree  
226 Invert Binary Tree Python Easy Binary Tree  
101 Symmetric Tree Python Easy Binary Tree  

Day 16 - Binary Tree Part 3

Question# Title Solution Difficulty Topics Nodes
104 Maximum Depth of Binary Tree Python Easy Binary Tree  
111 Minimum Depth of Binary Tree Python Easy Binary Tree  
222 Count Complete Tree Nodes Python Easy Binary Tree  

Day 17 - Binary Tree Part 4

Question# Title Solution Difficulty Topics Nodes
110 Balanced Binary Tree Python Easy Binary Tree  
257 Binary Tree Paths Python Easy Binary Tree  
404 Sum of Left Leaves Python Easy Binary Tree  

Day 18 - Binary Tree Part 5

Question# Title Solution Difficulty Topics Nodes
513 Find Bottom Left Tree Value Python Medium Binary Tree  
112 Path Sum Python Easy Binary Tree  
106 Construct Binary Tree from Inorder and Postorder Traversal Python Medium Binary Tree  

Day 19 - Binary Tree Part 6

Question# Title Solution Difficulty Topics Nodes
654 Maximum Binary Tree Python Medium Binary Tree  
617 Merge Two Binary Trees Python Easy Binary Tree  
700 Search in a Binary Search Tree Python Easy Binary Search Tree  
98 Validate Binary Search Tree Python Medium Binary Search Tree  

Day 20 - Binary Tree Part 7

Question# Title Solution Difficulty Topics Nodes
530 Minimum Absolute Difference in BST Python Easy Binary Search Tree  
501 Find Mode in Binary Search Tree Python Easy Binary Search Tree  
236 Lowest Common Ancestor of a Binary Tree Python Medium Binary Tree  

Day 22 - Binary Tree Part 8

Question# Title Solution Difficulty Topics Nodes
235 Lowest Common Ancestor of a Binary Search Tree Python Medium Binary Search Tree  
701 Insert into a Binary Search Tree Python Medium Binary Search Tree  
450 Delete Node in a BST Python Medium Binary Search Tree  

Day 23 - Binary Tree Part 9

Question# Title Solution Difficulty Topics Nodes
669 Trim a Binary Search Tree Python Medium Binary Search Tree  
108 Convert Sorted Array to Binary Search Tree Python Easy Binary Search Tree  
538 Convert BST to Greater Tree Python Medium Binary Search Tree  

Day 24 - Backtracking Part 1

Question# Title Solution Difficulty Topics Nodes
77 Combinations Python Medium Backtracking  

Day 25 - Backtracking Part 2

Question# Title Solution Difficulty Topics Notes
216 Combination Sum III Python Medium Backtracking  
17 Letter Combinations of a Phone Number Python Medium Backtracking  

Day 26 - Backtracking Part 3

Question# Title Solution Difficulty Topics Notes
39 Combination Sum Python Medium Backtracking  
40 Combination Sum II Python Medium Backtracking  
131 Palindrome Partitioning Python Medium Backtracking  

Day 27 - Backtracking Part 4

Question# Title Solution Difficulty Topics Notes
93 Restore IP Addresses Python Medium Backtracking  
78 Subsets Python Medium Backtracking  
90 Subsets II Python Medium Backtracking  

Day 29 - Backtracking Part 5

Question# Title Solution Difficulty Topics Notes
491 Non-decreasing Subsequences Python Medium Backtracking  
46 Permutations Python Medium Backtracking  
47 Permutations II Python Medium Backtracking  

Day 31 - Greedy Part 1

Question# Title Solution Difficulty Topics Notes
455 Assign Cookies Python Easy Greedy  
376 Wiggle Subsequence Python Medium Greedy  
53 Maximum Subarray Python Medium Greedy  

Day 32 - Greedy Part 2

Question# Title Solution Difficulty Topics Notes
122 Best Time to Buy and Sell Stock II Python Medium Greedy  
55 Jump Game Python Medium Greedy  
45 Jump Game II Python Medium Greedy  
MS Jump Game - MicroSoft Python – Greedy  

Day 33 - Greedy Part 3

Question# Title Solution Difficulty Topics Notes
1005 Maximize Sum Of Array After K Negations Python Easy Greedy  
134 Gas Station Python Medium Greedy  
135 Candy Python Hard Greedy  

Day 34 - Greedy Part 4

Question# Title Solution Difficulty Topics Notes
860 Lemonade Change Python Easy Greedy  
406 Queue Reconstruction by Height Python Medium Greedy  
452 Minimum Number of Arrows to Burst Balloons Python Medium Greedy  
9 Palindrome Number Python Easy Greedy  

Day 36 - Greedy Part 5

Question# Title Solution Difficulty Topics Notes
435 Non-overlapping Intervals Python Medium Greedy 2/3 review
763 Partition Labels Python Medium Greedy 2/3 review
56 Merge Intervals Python Medium Greedy 2/3 review

Day 37 - Greedy Part 6

Question# Title Solution Difficulty Topics Notes
738 Monotone Increasing Digits Python Medium Greedy  
968 Binary Tree Cameras Python Hard Greedy  

Day 38 - Dynamic Programming Part 1

Question# Title Solution Difficulty Topics Notes
509 Fibonacci Number Python Easy Dynamic Programming be cautious for (n+1)
70 Climbing Stairs Python Easy Dynamic Programming  
746 Min Cost Climbing Stairs Python Easy Dynamic Programming be caustious for (len(cost)) + 1

Day 39 - Dynamic Programming Part 2

Question# Title Solution Difficulty Topics Notes
62 Unique Paths Python Medium Dynamic Programming review and consider space save
63 Unique Paths II Python Medium Dynamic Programming  

Day 40 - Dynamic Programming Part 3

Question# Title Solution Difficulty Topics Notes
343 Integer Break Python Medium Dynamic Programming  
96 Unique Binary Search Trees Python Medium Dynamic Programming  

Day 41 - Dynamic Programming Part 4

Question# Title Solution Difficulty Topics Notes
46 携带研究材料-2D/1D Python – Dynamic Programming  
416 Partition Equal Subset Sum Python Medium Dynamic Programming  

Day 43 - Dynamic Programming Part 5

Question# Title Solution Difficulty Topics Notes
1049 Last Stone Weight II Python Medium Dynamic Programming  
494 Target Sum Python Medium Dynamic Programming  
474 Ones and Zeroes Python Medium Dynamic Programming  

Day 44 - Dynamic Programming Part 6

Question# Title Solution Difficulty Topics Notes
518 Coin Change II Python Medium Dynamic Programming  
377 Combination Sum IV Python Medium Dynamic Programming  

Day 45 - Dynamic Programming Part 7

Question# Title Solution Difficulty Topics Notes
70 Climbing Stairs Python Easy Dynamic Programming  
57 Advanced Climbing Stairs Python – Dynamic Programming  
322 Coin Change Python Medium Dynamic Programming  
279 Perfect Squares Python Medium Dynamic Programming  
amz Amazon Warehouse Distribution Python – Dynamic Programming  

Day 46 - Dynamic Programming Part 8

Question# Title Solution Difficulty Topics Notes
139 Word Break Python Medium Dynamic Programming  
56 Carrying Ore Resources Python – Dynamic Programming  
146 LRU Cache Python Medium Design  

Day 47 - Dynamic Programming Part 9

Question# Title Solution Difficulty Topics Notes
198 House Robber Python Medium Dynamic Programming  
213 House Robber II Python Medium Dynamic Programming  
337 House Robber III Python Medium Dynamic Programming  

Day 48 - Dynamic Programming Part 10

Question# Title Solution Difficulty Topics Notes
121 Best Time to Buy and Sell Stock Python Easy Dynamic Programming  
122 Best Time to Buy and Sell Stock II Python Medium Dynamic Programming  

Day 50 - Dynamic Programming Part 11

Question# Title Solution Difficulty Topics Notes
123 Best Time to Buy and Sell Stock III Python Hard Dynamic Programming  
188 Best Time to Buy and Sell Stock IV Python Hard Dynamic Programming  

Day 51 - Dynamic Programming Part 12

Question# Title Solution Difficulty Topics Notes
309 Best Time to Buy and Sell Stock with Cooldown Python Medium Dynamic Programming  
714 Best Time to Buy and Sell Stock with Transaction Fee Python Medium Dynamic Programming  

Day 52 - Dynamic Programming Part 13

Question# Title Solution Difficulty Topics Notes
300 Longest Increasing Subsequence Python Medium Dynamic Programming  
674 Longest Continuous Increasing Subsequence Python Easy Dynamic Programming  
718 Maximum Length of Repeated Subarray Python Medium Dynamic Programming  

Day 53 - Dynamic Programming Part 14

Question# Title Solution Difficulty Topics Notes
1143 Longest Common Subsequence Python Medium Dynamic Programming  
1035 Uncrossed Lines Python Medium Dynamic Programming  
53 Maximum Subarray Python Medium Dynamic Programming  

Day 54 - Dynamic Programming Part 15

Question# Title Solution Difficulty Topics Notes
392 Is Subsequence Python Easy Dynamic Programming  
115 Distinct Subsequences Python Hard Dynamic Programming  

Day 55 - Dynamic Programming Part 16

Question# Title Solution Difficulty Topics Notes
583 Delete Operation for Two Strings Python Medium Dynamic Programming  
72 Edit Distance Python Hard Dynamic Programming  

Day 57 - Dynamic Programming Part 17

Question# Title Solution Difficulty Topics Notes
647 Palindromic Substrings Python Medium Dynamic Programming  
516 Longest Palindromic Subsequence Python Medium Dynamic Programming  

Day 58 - Monotonic Stack Part 1

Question# Title Solution Difficulty Topics Notes
739 Daily Temperatures Python Medium Monotonic Stack  
496 Next Greater Element I Python Easy Monotonic Stack  

Day 59 - Monotonic Stack Part 2

Question# Title Solution Difficulty Topics Notes
503 Next Greater Element II Python Medium Monotonic Stack  
42 Trapping Rain Water Python Hard Monotonic Stack  

Day 60 - Monotonic Stack Part 3

Question# Title Solution Difficulty Topics Notes
84 Largest Rectangle in Histogram Python Hard Monotonic Stack