Problems
May 23, 2023
Maximum subsequence score
We can use a heap to store the elements in the array. Then, we can pop the elements from the heap and add them to the result. We will also keep track of the sum of the elements in the heap. If the...
ReadMay 23, 2023
Sum in a matrix
We will iterate over each row and sort them. Then we iterate over each column and get the maximum value of the column. Finally, we return the sum of the maximum values. Time complexity:...
ReadMay 22, 2023
Find three consecutive integers that sum to a given number
We will check whether the number is divisible by 3. If it is, we can return the three consecutive numbers. Otherwise, we will return empty arry.
Time complexity: O(1)
Space...
May 22, 2023
Split a circular linked list
We can use a slow and fast pointer to find the middle of the linked list. Then, we can set the next pointer of the last node to None to split the linked list into two. We can then return...
May 21, 2023
Kth largest sum in a binary tree
We will traverse the whole tree with BFS and store each levels sum in a list. Then, we will use a heap to get the k-th largest sum. We will also check if the tree doesn't have enough...
May 20, 2023
Maximum profit from trading stocks
This is a classic 0-1 knapsack problem. We can use dynamic programming to solve this problem. We can iterate through the prices array and calculate the maximum profit for each day. The maximum profit...
ReadMay 20, 2023
K-th smallest prime fraction
We can use a heap to store the fractions. We can start with the fraction 1/n and add the next smallest fraction to the heap. We can repeat this process until we have added k...
May 19, 2023
Check if word equals summation of two words
We can convert the words to integers and check if the sum of the first two integers equals the third integer.
Time complexity: O(n) where n is the length of the longest word.
Space...
May 19, 2023
The kth factor of n
We can iterate through the numbers from 1 to n and check if the number is a factor of n. If it is, we decrement k by 1. If k is 0, we return the number.
Time complexity: O(n) where n...
May 18, 2023
Number of adjacent elements with the same color
We can use a hashmap to store the indices of each color. Then, we can iterate through the array and check if the adjacent elements have the same color.
Time complexity: O(n) where n...