In "Easy"
![Squares of a Sorted Array](/assets/img/blog/squares-sorted-array.png)
Squares of a Sorted Array
Given an integer array nums sorted in non-decreasing order, return an array of the squares of each number sorted in non-decreasing order....
![Check If N and Its Double Exist](/assets/img/blog/searching-items-array.png)
Check If N and Its Double Exist
Given an array arr of integers, check if there exist two indices i and j such that :
![Remove Element](/assets/img/blog/remove-element.png)
Remove Element
Given an integer array nums and an integer val, remove all occurrences of val in nums in-place. The relative order of the...
![Merge Sorted Array](/assets/img/blog/merge-sorted-array.png)
Merge Sorted Array
You are given two integer arrays nums1 and nums2, sorted in non-decreasing order, and two integers m and n, representing the number...
![First Unique Character in a String](/assets/img/blog/first-unique-character-string.png)
First Unique Character in a String
Given a string s, find the first non-repeating character in it and return its index ....
![Duplicate Zeros](/assets/img/blog/duplicate-zeros.png)
Duplicate Zeros
Given a fixed-length integer array arr, duplicate each occurrence of zero, shifting the remaining elements to...
![Remove Duplicates from Sorted Array](/assets/img/blog/deleting-items-from-array.png)
Remove Duplicates from Sorted Array
Given an integer array nums sorted in non-decreasing order, remove the duplicates in-place such that each unique element appears only once....
![Find Numbers with Even Number of Digits](/assets/img/blog/find-numbers-even-number-digits.png)
Find Numbers with Even Number of Digits
Given an array nums of integers, return how many of them contain an even number of digits.
![Max Consecutive Ones](/assets/img/blog/max-consecutive-ones.png)
Max Consecutive Ones
Given a binary array nums, return the maximum number of consecutive 1's in the array.
In "Medium"
![String Compression](/assets/img/blog/string-compression.png)
String Compression
Given an array of characters chars, compress it using the following algorithm:
![Validate Binary Search Tree](/assets/img/blog/validate-binary-search-tree.png)
Validate Binary Search Tree
Given the root of a binary tree, determine if it is a valid binary search tree (BST).
![Subarray Sum Equals K](/assets/img/blog/subarray-sum-equals-k.png)
Subarray Sum Equals K
Given an array of integers nums and an integer k, return the total number of subarrays whose sum equals...
![Candy Crush](/assets/img/blog/candy-crush.png)
Candy Crush
This question is about implementing a basic elimination algorithm for Candy Crush.
![Add Two Numbers](/assets/img/blog/add-two-numbers.png)
Add Two Numbers
You are given two non-empty linked lists representing two non-negative integers. The digits are stored in reverse order,...