Click here to see the problem details. Problem Overview The problem description is pretty straightforward. We are given two sorted Linked List. And we have to merge those given Lists into one sorted list. That’s the problem. Suppose our given two lists are 1 -> 3 and 2 -> 4. And the result will be […]
Merge Two Sorted Lists | LeetCode 21 | Python | Solution Read More »
Click here to see the problem details. Read the problem details first. Concept This is clearly a Tree related problem and a medium-type problem. In my sense, it’s not that difficult if you have a basic concept about BST (Binary Search Tree). BST is also a Binary Tree. So what is a Binary Search Tree?
Insert into a Binary Search Tree | LeetCode 701 | Python | Solution Read More »
Click here to see the problem details. It’s an easy LeetCode problem with straightforward problem details. In a simple word, we will be given a sentence to check it is Pangram or not. So, what is Pangram? According to the problem description, “A pangram is a sentence where every letter of the English alphabet appears
Check if the Sentence Is Pangram | LeetCode 1832 | Python | Solution Read More »
Click here to see the problem details on LeetCode. Before solving this problem, we have to know about palindrome. According to the definition of Wikipedia: A palindrome is a word, number, phrase, or other sequence of characters which reads the same backward as forward, such as madam or racecar. Wikipedia The problem says that we
Valid Palindrome | LeetCode 125 | Python | Solution Read More »
Click here to see the problem details. Problem Overview The problem description is pretty precise. It says that we have to return the reverse version of the given string. But we can only reverse letters. Characters that are not a letter stay in the same place. Only letters will change their position. Let’s see an
Reverse Only Letters | LeetCode 917 | Python | Solution Read More »
Click here to see the problem on LeetCode. The problem description is pretty straightforward. We have to return all the nodes’ values following the preorder traversal algorithm. I can assume that you have a basic understanding of Tree data structure. Mainly, there are four types of traversing algorithms in Binary Tree. Preorder traversal is one
Binary Tree Preorder Traversal | LeetCode 144 | Python | Solution Read More »
Here is the link to the problem. See the problem description. We have to check the given array is monotonic or not. What is a monotonic array? “An array is monotonic if it is either monotone increasing or monotone decreasing.” line quoted from the problem description. The formula is:For checking increasing monotone of the given
Monotonic Array | LeetCode 896 | Python | Solution Read More »
This one is a simple SQL problem. Here is the link to this problem. This one is an absolute beginner type problem. We have to query all the duplicates emails from the given table. The name of the table is Person. The code is almost self-explanatory. All SQL keywords are written in uppercase letters. It’s
Duplicate Emails | LeetCode 182 | SQL | Solution Read More »
Click here to see the problem details. The problem is simple. We have to find at least one duplicate in the given array. If we found any duplicate number, we will return True. Otherwise, we will return False. That’s the simple idea about the problem. And given array’s elements will be integers. Let’s see two
Contains Duplicate | LeetCode 217 | Python | Solution Read More »
Click here to see the problem in LeetCode. And read the problem’s details. This one is a pretty simple problem. We will be given an integer array. We have to find the largest element’s index, which is must be at least twice as much as every other number in the array. If it’s not matched
Largest Number At Least Twice of Others | LeetCode 747 | Python | Solution Read More »