My Leet Code Repository

This is my leet code repository for interview preparation and my own entertainment.

by Ditra Amadia

Problems

Total: 80

• Easy: 39
• Medium: 34
• Hard: 7

No	Problem	Difficulty	Runtime (ms)	Time Complexity (Big O)	Language
1	Two Sum	Easy	13	$$O(n)$$
2	Add Two Numbers	Medium	15	$$O(n)$$
3	Longest Substring Without Repeating Characters	Medium	10	$$O(n)$$
4	Median of Sorted Arrays	Hard	23	$$O(\log n)$$
5	Longest Palindromic Substring	Medium	11	$$O(n^2)$$
6	Zigzag Conversion	Medium	3	$$O(n)$$
7	Reverse Integer	Medium	0	$$O(n)$$
8	String to Integer (atoi)	Medium	0	$$O(n)$$
9	Palindrome Number	Easy	9	$$O(n)$$
10	Regular Expression	Hard	11	$$O(n)$$
11	Container With Most Water	Medium	46, 67	$$O(n)$$
12	Integer to Roman	Medium	3	$$O(1)$$
13	Roman to Integer	Easy	15	$$O(n)$$
14	Longest Common Prefix	Easy	3	$$O(n)$$
15	3Sum	Medium	50	$$O(n^2)$$
16	3Sum Closest	Medium	15	$$O(n^2)$$
17	Letter Combinatino of a Phone Number	Medium	4	$$O(n^n)$$
18	4Sum	Medium	315	$$O(n^3)$$
19	Remove Nth Node From End Of List	Medium	0	$$O(n)$$
20	Valid Parentheses	Easy	0	$$O(n)$$
21	Merge Two Sorted Lists	Easy	0	$$O(n)$$
22	Generate Parentheses	Medium	0	$$O\left(\frac{4^n}{\sqrt{n}}\right)$$
23	Merge K Sorted Lists	Hard	11	$$O(n \cdot \log k)$$
24	Swap Nodes in Pairs	Medium	0	$$O(n)$$
25	Reverse Nodes in k-Group	Hard	0	$$O(n)$$
26	Remove Duplicates from Sorted Array	Easy	3	$$O(n)$$
27	Remove Element	Easy	0	$$O(n)$$
28	Find the Index of the First Occurence in a String	Easy	0	$$O(n^2)$$
29	Divide Two Integers	Medium	0	$$O(\log n)$$
30	Substring with Concatenation of All Words	Hard	17	$$O(n \cdot m)$$
31	Next Permutation	Medium	0	$$O(n \cdot \log n)$$
32	Longest Valid Parentheses	Hard	2	$$O(n)$$
33	Search in Rotated Sorted Array	Medium	0	$$O(\log n)$$
34	Find First and Last Position of Element in Sorted Array	Medium	0	$$O(\log n)$$
35	Search Insert Position	Easy	0	$$O(\log n)$$
58	Length of Last Word	Easy	0	$$O(n)$$
66	Plus One	Easy	0	$$O(n)$$
67	Add Binary	Easy	0	$$O(n)$$
69	Sqrt(x)	Easy	0	$$O(\log n)$$
70	Climbing Stairs	Easy	0	$$O(n)$$
83	Remove Duplicates from Sorted List	Easy	0	$$O(n)$$
88	Merge Sorted Array	Easy	0	$$O(n)$$
94	Binary Tree Inorder Traversal	Easy	0	$$O(n)$$
100	Same Tree	Easy	0	$$O(2^n)$$
101	Symmetric Tree	Easy	3	$$O(2^n)$$
104	Maximum Depth of Binary Tree	Easy	5	$$O(2^n)$$
108	Convert Sorted Array to Binary Search Tree	Easy	7	$$O(n)$$
110	Balanced Binary Tree	Easy	4	$$O(2^n)$$
151	Reverse Words in a String	Medium	0	$$O(n)$$
167	Two Sum II (Input Array is Sorted)	Medium	3	$$O(n)$$
206	Reversed Linked List	Easy	0	$$O(n)$$
238	Product of Array Except Self	Medium	19	$$O(n)$$
283	Move Zeroes	Easy	3	$$O(n)$$
334	Increasing Triplet Subsequence	Medium	11	$$O(n)$$
345	Reverse Vowels of a String	Easy	4	$$O(n)$$
392	Is Subsequence	Easy	0	$$O(n)$$
394	Decode String	Medium	0	$$O(n)$$
404	Sum of Left Leaves	Easy	0	$$O(n)$$
443	String Compression	Medium	0	$$O(n)$$
467	Unique Substrings in Wraparound String	Medium	49	$$O(n)$$
472	Concatenated Words	Hard	151	$$O(n \cdot m^2)$$
605	Can Place Flowers	Easy	0	$$O(n)$$
643	Maximum Average Subarray I	Easy	81	$$O(k)$$
724	Find Pivot Index	Easy	1	$$O(n)$$
735	Asteroid Collision	Medium	0	$$O(n)$$
832	Flipping an Image	Easy	0	$$O(mn)$$
897	Increasing Order Search Tree	Easy	0	$$O(n)$$
1004	Max Consecutive Ones III	Medium	59	$$O(n)$$
1071	Greatest Common Divisor of Strings	Easy	0	$$O(\min(m,n))$$
1207	Unique Number of Occurrences	Easy	0	$$O(n)$$
1431	Kids with The Greatest Number of Candies	Easy	0	$$O(n)$$
1456	Maximum Number of Vowels in a Substring of Given Length	Medium	74	$$O(k)$$
1493	Longest Subarray of 1's After Deleting One Element	Medium	58	$$O(n)$$
1657	Determine if Two Strings Are Close	Medium	84	$$O(n)$$
1679	Max Number of K-Sum Pairs	Medium	487	$$O(n)$$
1732	Find the Highest Altitude	Easy	0	$$O(n)$$
1768	Merge Strings Alternately	Easy	35	$$O(n)$$
2215	Find the Difference of Two Arrays	Easy	2	$$O(n)$$
2352	Equal Row and Column Pairs	Medium	3	$$O(n^2)$$
2390	Removing Stars From a String	Medium	88	$$O(n)$$