Practice-Coding-Questions
Personal Practice Set - Doing One a Day (sometimes) in a Variety of Languages (Mostly Python)!
# |
Difficulty |
Problem |
Solution |
1 |
Easy |
Two Sum |
Java, Python, Ruby |
2 |
Medium |
Add Two Numbers |
C |
3 |
Medium |
Longest Substring Without Repeating Characters |
Python |
4 |
Hard |
Median of Two Sorted Arrays |
Python |
5 |
Medium |
Longest Palindromic Substring |
Python |
6 |
Medium |
Zig Zag Conversion |
Java |
7 |
Easy |
Reverse Integer |
Python |
8 |
Medium |
String to Integer |
Ruby |
9 |
Easy |
Palindrome Number |
C, Java, Python, Swift |
10 |
Hard |
Regular Expression Matching |
Python |
11 |
Medium |
Container With Most Water |
Python |
12 |
Medium |
Integer to Roman |
Python |
13 |
Easy |
Roman to Integer |
C, Python |
14 |
Easy |
Longest Common Prefix |
Python |
15 |
Medium |
3Sum |
Python |
16 |
Medium |
3Sum Closest |
Python |
17 |
Medium |
Letter Combinations of a Phone Number |
Python |
18 |
Medium |
4Sum |
Python |
19 |
Medium |
Remove Nth Node From End of List |
Python |
20 |
Easy |
Valid Parentheses |
Java, Python |
21 |
Easy |
Merge Two Sorted Lists |
Java, Python |
22 |
Medium |
Generate Parentheses |
Python |
23 |
Hard |
Merge k Sorted Lists |
Python |
24 |
Medium |
Swap Node in Pairs |
Python |
25 |
Hard |
Reverse Nodes in k-Group |
Python |
26 |
Easy |
Remove Duplicates from Sorted Array |
C, Python |
27 |
Easy |
Remove Element |
Python |
28 |
Easy |
Implement strStr() |
C, Python |
29 |
Medium |
Divide Two Integers |
Python |
31 |
Medium |
Next Permutation |
Python |
33 |
Medium |
Search in Rotated Sorted Array |
Python |
34 |
Medium |
Find First and Last Position of Element in Sorted Array |
Python |
35 |
Easy |
Search Insert Position |
Go, Java, JavaScript, Scala |
36 |
Medium |
Valid Sudoku |
Python |
38 |
Easy |
Count and Say |
Python |
39 |
Medium |
Combination Sum |
Python |
40 |
Medium |
Combination Sum II |
Python |
42 |
Hard |
Trapping Rain Water |
Python |
43 |
Medium |
Multiply Strings |
Python |
44 |
Hard |
Wildcard Matching |
Python |
46 |
Medium |
Permutations |
Python |
47 |
Medium |
Permutations II |
Python |
48 |
Medium |
Rotate Image |
Python |
49 |
Medium |
Group Anagrams |
Python |
50 |
Medium |
Pow(x, n) |
Python |
53 |
Easy |
Maximum Subarray |
Java |
54 |
Medium |
Spiral Matrix |
Python |
55 |
Medium |
Jump Game |
Python |
56 |
Medium |
Merge Intervals |
Python |
58 |
Easy |
Length of Last Word |
Python |
62 |
Medium |
Unique Paths |
Python |
63 |
Medium |
Unique Paths II |
Python |
64 |
Medium |
Minimum Path Sum |
Python |
66 |
Easy |
Plus One |
Python |
67 |
Easy |
Add Binary |
Python |
69 |
Easy |
Sqrt() |
Python |
70 |
Easy |
Climbing Stairs |
C |
76 |
Hard |
Minimum Window Substring |
Python |
78 |
Medium |
Subsets |
Python |
79 |
Medium |
Word Search |
Python |
83 |
Easy |
Remove Duplicates from Sorted List |
Python |
84 |
Hard |
Largest Rectangle in Histogram |
Python |
85 |
Hard |
Maximal Rectangle |
Python |
88 |
Easy |
Merge Sorted Array |
Python |
100 |
Easy |
Same Tree |
Python |
101 |
Easy |
Symmetric Tree |
Python |
102 |
Medium |
Binary Tree Level Order Traversal |
Python |
104 |
Easy |
Maximum Depth of Binary Tree |
Python |
105 |
Medium |
Construct Binary Tree from Preorder and Inorder Traversal |
Python |
106 |
Medium |
Construct Binary Tree from Inorder and Postorder Traversal |
Python |
107 |
Easy |
Binary Tree Level Order Traversal II |
Python |
108 |
Easy |
Convert Sorted Array to Binary Search Tree |
Python |
110 |
Easy |
Balanced Binary Tree |
Python |
111 |
Easy |
Minimum Depth of Binary Tree |
Python |
112 |
Easy |
Path Sum |
Python |
118 |
Easy |
Pascal's Triangle |
Python |
121 |
Easy |
Best Time to Buy and Sell Stock |
Python |
122 |
Easy |
Best Time to Buy and Sell Stock II |
Python |
123 |
Hard |
Best Time to Buy and Sell Stock III |
Python |
125 |
Easy |
Valid Palindrome |
Python |
127 |
Medium |
Word Ladder |
Python |
133 |
Medium |
Clone Graph |
Python |
136 |
Easy |
Single Number |
Python |
137 |
Medium |
Single Number II |
Python |
139 |
Medium |
Word Break |
Python |
141 |
Easy |
Linked List Cycle |
Python |
142 |
Medium |
Linked List Cycle II |
Python |
146 |
Hard |
LRU Cache |
Python |
148 |
Medium |
Sort List |
Python |
153 |
Medium |
Find Minimum in Rotated Sorted Array |
Python |
155 |
Easy |
Min Stack |
Python |
162 |
Medium |
Find Peak Element |
Python |
168 |
Easy |
Excel Sheet Column Title |
Python |
171 |
Easy |
Excel Sheet Column Number |
Python |
173 |
Medium |
Binary Search Tree Iterator |
Python |
188 |
Hard |
Best Time to Buy and Sell Stock IV |
Python |
191 |
Easy |
Number of 1 Bits |
Python |
196 |
Easy |
Delete Duplicate Emails |
SQL |
200 |
Medium |
Number of Islands |
Python |
204 |
Easy |
Count Primes |
Python |
206 |
Easy |
Reverse Linked List |
Python |
207 |
Medium |
Course Schedule |
Python |
208 |
Medium |
Implement Trie |
Java, Python |
215 |
Medium |
Kth Largest Element in an Array |
Python |
218 |
Hard |
The Skyline Problem |
Python |
226 |
Easy |
Invert Binary Tree |
Python |
231 |
Easy |
Power Of Two |
Python |
234 |
Easy |
Palindrome Linked List |
Python |
235 |
Easy |
Lowest Common Ancestor of a Binary Search Tree |
Python |
236 |
Medium |
Lowest Common Ancestor of a Binary Tree |
Python |
237 |
Easy |
Delete Node in a Linked List |
Python |
238 |
Medium |
Product of Array Except Self |
Python |
240 |
Medium |
Search a 2D Matrix II |
Python |
258 |
Easy |
Add Digits |
Python |
268 |
Easy |
Missing Number |
Python |
273 |
Hard |
Integer to English Words |
Python |
283 |
Easy |
Move Zeroes |
Python |
287 |
Medium |
Find the Duplicate Number |
Python |
295 |
Hard |
Find Median from Data Stream |
Python |
297 |
Hard |
Serialize and Deserialize Binary Tree |
Java |
301 |
Hard |
Remove Invalid Parentheses |
Python |
310 |
Medium |
Minimum Height Trees |
Python |
341 |
Medium |
Flatten Nested List Iterator |
Python |
344 |
Easy |
Reverse String |
Python |
388 |
Medium |
Longest Absolute File Path |
Python |
389 |
Easy |
Find the Difference |
Python |
461 |
Easy |
Hamming Distance |
Python |
495 |
Medium |
Teemo Attacking |
Python |
535 |
Medium |
Encode and Decode TinyURL |
Python |
733 |
Easy |
Flood Fill |
Python |
771 |
Easy |
Jewels and Stones |
Python |
1114 |
Easy |
Print in Order |
Python |
30 Days of Code Challenge
Cracking the Coding Interview 6th Edition Python Solutions