Problems
November 18, 2022
Linked list components
We will create a hashset with the nums. Then we will traverse the linked list and check if the current node is in the hashset. If yes, that means both are connected. We will then traverse the linked...
ReadNovember 17, 2022
Find the highest altitude
We will iterate over the gain array and add the gain to the current altitude. We will update the maximum altitude if the current altitude is greater than the maximum altitude. We can also achieve...
ReadNovember 17, 2022
Finding the users active minutes
We will use a hashset to count the unique logs for each user. Then we iterate over that, take the length of the hashset and add it to the result.
Time complexity: O(n)
Space...
November 17, 2022
Number of digit one
We will create a function countDigitOne which will take a number as input. We will initialize a variable count to 0. We will initialize a variable...
November 17, 2022
Rectangle area
We will find the area of the first rectangle and the second rectangle. We will find the area of the overlapping rectangle by finding the length and breadth of the overlapping rectangle. We will...
ReadNovember 17, 2022
Symmetric tree
We will create a function isMirror which will take two nodes as input. If both the nodes are None, we will return True. If one of the nodes is...
November 16, 2022
Construct binary search tree from preorder traversal
As preorder traversal is given, we know the first element will be the root. We will create a function witg a bound the maximum number it will handle. The left recursion will take the elements smaller...
ReadNovember 16, 2022
Count days spent together
We will use a helper function to get the number of days from the beginning of the year to the given date. Then take the maximum of arrival date and minimum of departure date and subtract the minimum...
ReadNovember 16, 2022
Delete nodes and return forest
We will use DFS for deleting the nodes. We recursively delete the left and right subtrees and then return the root. If the root is in the set, we return the left and right subtrees, and if the root...
ReadNovember 16, 2022
Insert into a binary search tree
We will use DFS for inserting. We recursively insert the left and right subtrees and then return the root. If the root is null, we return the new node. If the root is greater than the value, we...
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