LeetCode Solutions

Algorithms

• Math
• Bit Manipulation
• Array
• String
• Matrix
• Hash Table
• Binary Search
• Sorting
• Two Pointers
• Dynamic Programming

Explained Solutions

#	Title	Explanation	Complexity	Difficulty
9	Palindrome Number	Explained Solution	Time - O(log10(n)) Space - O(1)	Easy
50	Pow(x, n)	Explained Solution	Time - O(log2(n)) Space - O(1)	Medium
191	Number of 1 Bits	Explained Solution	Time - O(1) Space - O(1)	Easy
1431	Kids With the Greatest Number of Candies	Commented Solution	Time - O(n) Space - O(n)	Easy
1470	Shuffle The Array	Explained Solution	Time - O(n) Space - O(1)	Easy
2129	Capitalize the Title	Explained Solution	Time - O(n) Space - O(1)	Easy

Math

#	Title	Solution	Complexity	Difficulty
7	Reverse Integer	C++ Java	Time - O(log10(n)) Space - O(1)	Medium
9	Palindrome Number	C++ Java	Time - O(log10(n)) Space - O(1)	Easy
50	Pow(x, n)	Java	Time - O(log2(n)) Space - O(1)	Medium
67	Add Binary	Java	Time - O(max(n, m)) Space - O(max(n, m))	Easy
172	Factorial Trailing Zeroes	C++ Java	Time - O(log5(n)) Space - O(1)	Medium
231	Power Of Two	C++ Java	Time - O(1) Space - O(1)	Easy
263	Ugly Number	C++ Java	Time - O(log2(n)) Space - O(1)	Easy
1137	N-th Tribonacci Number	C++ Java	Time - O(n) Space - O(1)	Easy
1281	Subtract the Product and Sum of Digits of an Integer	C++ Java	Time - O(n) Space - O(1)	Easy
1342	Number of Steps to Reduce a Number to Zero	C++ Java	Time - O(log2(n)) Space - O(1)	Easy
1551	Minimum Operations to Make Array Equal	C++ Java	Time - O(1) Space - O(1)	Medium
1688	Count of Matches in Tournament	C++ Java	Time - O(1) Space - O(1)	Easy

Bit Manipulation

#	Title	Solution	Complexity	Difficulty
191	Number of 1 Bits	C++ Java	Time - O(1) Space - O(1)	Easy
231	Power Of Two	C++ Java	Time - O(1) Space - O(1)	Easy
476	Number Complement	C++ Java	Time - O(log2(n)) Space - O(1)	Easy
1720	Decode XORed Array	C++ Java	Time - O(n) Space - O(1)	Easy
1009	Complement of Base 10 Integer	C++ Java	Time - O(log2(n)) Space - O(1)	Easy

Array

#	Title	Solution	Complexity	Difficulty
1	Two Sum	Java	Time - O(n) Space - O(n)	Easy
80	Remove Duplicates from Sorted Array II	C++ Java	Time - O(n) Space - O(1)	Medium
136	Single Number	C++ Java	Time - O(n) Space - O(1)	Easy
162	Find Peak Element	C++ Java	Time - O(log2(n)) Space - O(1)	Medium
500	Keyboard Row	Java	Time - O(N) Space - O(n)	Easy
1094	Car Pooling	C++Java	Time - O(n) Space - O(n)	Medium
848	Shifting Letters	C++ Java	Time - O(n) Space - O(1)	Medium
1207	Unique Number of Occurrences	Java	Time - O(n) Space - O(n)	Easy
1295	Find Numbers with Even Number of Digits	C++ Java	Time - O(n) Space - O(1)	Easy
1365	How Many Numbers Are Smaller Than the Current Number	C++ Java	Time - O(n + m) Space - O(m)	Easy
1431	Kids With the Greatest Number of Candies	C++ Java	Time - O(n) Space - O(n)	Easy
1470	Shuffle The Array	C++ Java	Time - O(n) Space - O(1)	Easy
1480	Running Sum of 1d Array	C++ Java	Time - O(n) Space - O(1)	Easy
1512	Number of Good Pairs	C++ Java	Time - O(n) Space - O(n)	Easy
1550	Three Consecutive Odds	C++ Java	Time - O(n) Space - O(1)	Easy
1646	Get Maximum in Generated Array	C++ Java	Time - O(n) Space - O(n)	Easy
1662	Check If Two String Arrays are Equivalent	C++ Java	Time - O(n) Space - O(1)	Easy
1672	Richest Customer Wealth	C++ Java	Time - O(m * n) Space - O(1)	Easy
1720	Decode XORed Array	C++ Java	Time - O(n) Space - O(1)	Easy
1748	Sum of Unique Elements	C++ Java	Time - O(n) Space - O(m)	Easy
1909	Remove One Element to Make the Array Strictly Increasing	C++ Java	Time - O(n) Space - O(1)	Easy
1929	Concatenation of Array	C++ Java	Time - O(n) Space - O(1)	Easy
1979	Find Greatest Common Divisor of Array	C++ Java	Time - O(n) Space - O(1)	Easy
1980	Find Unique Binary String	C++ Java	Time - O(n) Space - O(1)	Medium
2006	Count Number of Pairs With Absolute Difference K	C++ Java	Time - O(n + m) Space - O(m)	Easy
2011	Final Value of Variable After Performing Operations	C++ Java	Time - O(n) Space - O(m)	Easy
2023	Number of Pairs of Strings With Concatenation Equal to Target	Java	Time - O(n * m) Space - O(n)	Easy
2078	Two Furthest Houses With Different Colors	C++Java	Time - O(n) Space - O(1)	Easy
2114	Maximum Number of Words Found in Sentences	C++Java	Time - O(n * m) Space - O(1)	Easy
189	Rotate Array	Java	Time - O(n) Space - O(1)	Medium

String

#	Title	Solution	Complexity	Difficulty
49	Group Anagrams	Java	Time - O(n * m) Space - O(n)	Medium
125	Valid Palindrome	C++ Java	Time - O(n) Space - O(1)	Easy
151	Reverse Words in a String	Java	Time - O(n * m) Space - O(n)	Medium
344	Reverse String	C++ Java	Time - O(n) Space - O(1)	Easy
500	Keyboard Row	Java	Time - O(n) Space - O(n)	Easy
796	Rotate String	C++ Java	Time - O(m * n) Space - O(1)	Easy
848	Shifting Letters	C++ Java	Time - O(n) Space - O(1)	Medium
1446	Consecutive Characters	C++ Java	Time - O(n) Space - O(1)	Easy
1461	Check If a String Contains All Binary Codes of Size K	Java	Time - O(n) Space - O(2k)	Medium
1528	Shuffle String	C++ Java	Time - O(n) Space - O(1)	Easy
1544	Make The String Great	C++ Java	Time - O(n) Space - O(1)	Easy
1662	Check If Two String Arrays are Equivalent	C++ Java	Time - O(n) Space - O(1)	Easy
1678	Goal Parser Interpretation	C++ Java	Time - O(n) Space - O(1)	Easy
1790	Check if One String Swap Can Make Strings Equal	C++ Java	Time - O(n) Space - O(1)	Easy
1796	Second Largest Digit in a String	C++ Java	Time - O(n) Space - O(1)	Easy
1816	Truncate Sentence	C++ Java	Time - O(n) Space - O(1)	Easy
1844	Replace All Digits with Characters	C++ Java	Time - O(n) Space - O(1)	Easy
1945	Sum of Digits of String After Convert	C++ Java	Time - O(n) Space - O(1)	Easy
1941	Check if All Characters Have Equal Number of Occurrences	C++ Java	Time - O(n) Space - O(1)	Easy
2000	Reverse Prefix of Word	C++ Java	Time - O(n) Space - O(1)	Easy
2042	Check if Numbers Are Ascending in a Sentence	C++ Java	Time - O(n) Space - O(1)	Easy
2103	Rings and Rods	C++ Java	Time - O(n) Space - O(1)	Easy
1456	Maximum Number of Vowels in a Substring of Given Length	C++ Java	Time - O(n) Space - O(1)	Medium
2068	Check Whether Two Strings are Almost Equivalent	C++ Java	Time - O(n) Space - O(1)	Easy
2124	Check if All A's Appears Before All B's	C++ Java	Time - O(n) Space - O(1)	Easy
2129	Capitalize the Title	Explanation C++ Java	Time - O(n) Space - O(1)	Easy

Matrix

#	Title	Solution	Complexity	Difficulty
566	Reshape the Matrix	C++ Java	Time - O(m * n) Space - O(1)	Easy
867	Transpose Matrix	C++ Java	Time - O(m * n) Space - O(1)	Easy
1572	Matrix Diagonal Sum	C++ Java	Time - O(n) Space - O(1)	Easy
1672	Richest Customer Wealth	C++ Java	Time - O(m * n) Space - O(1)	Easy

Hash Table

#	Title	Solution	Complexity	Difficulty
1	Two Sum	Java	Time - O(n) Space - O(n)	Easy
49	Group Anagrams	Java	Time - O(n * m) Space - O(n)	Medium
500	Keyboard Row	Java	Time - O(n) Space - O(n)	Easy
1207	Unique Number of Occurrences	Java	Time - O(n) Space - O(n)	Easy
1365	How Many Numbers Are Smaller Than the Current Number	C++ Java	Time - O(n + m) Space - O(m)	Easy
2053	Kth Distinct String in an Array	Java	Time - O(n) Space - O(n)	Easy
2085	Count Common Words With One Occurrence	Java	Time - O(n + m) Space - O(n)	Easy

Binary Search

#	Title	Solution	Complexity	Difficulty
162	Find Peak Element	C++ Java	Time - O(log2(n)) Space - O(1)	Medium
704	Binary Search	C++ Java	Time - O(log2(n)) Space - O(1)	Easy

Sorting

#	Title	Solution	Complexity	Difficulty
1365	How Many Numbers Are Smaller Than the Current Number	C++ Java	Time - O(n + m) Space - O(m)	Easy

Two Pointers

#	Title	Solution	Complexity	Difficulty
80	Remove Duplicates from Sorted Array II	C++ Java	Time - O(n) Space - O(1)	Medium

Dynamic Programming

#	Title	Solution	Complexity	Difficulty
264	Ugly Number II	C++ Java	Time - O(n) Space - O(n)	Medium
1137	N-th Tribonacci Number	C++ Java	Time - O(n) Space - O(1)	Easy
1646	Get Maximum in Generated Array	C++ Java	Time - O(n) Space - O(n)	Easy