10+ ACKO Software Developer Intern Interview Questions and Answers

The goal is to determine the minimum number of scalar multiplications needed to multiply a chain of matrices together.

• Understand the matrix chain multiplication problem statement and how the dimensions of matrices are defined by the input array.

• Implement a dynamic programming approach to find the minimum cost of matrix multiplication.

• Consider the constraints provided and optimize the solution accordingly.

• Test the solution with different input arrays to ensure correctness.

• Focu...read more

Find maximum sum of disjoint pairs with specific difference in an array.

• Sort the array in non-decreasing order.

• Iterate through the array and form pairs with absolute difference less than K.

• Keep track of the sum of disjoint pairs to maximize it.

• Return the maximum sum obtained.

Rearrange an array such that all zero elements appear at the beginning, followed by non-zero elements, maintaining relative order of non-zero elements.

• Iterate through the array and move all zero elements to the left side of the array while maintaining the relative order of non-zero elements.

• Use two pointers approach to swap elements efficiently.

• Ensure to solve the problem in linear time and constant space complexity.

• Example: Input: [1, 1, 0, 2, 0], Output: [0, 0, 1, 1, 2]

Find all pairs of elements in an array that add up to a given target.

• Iterate through the array and for each element, check if the complement (target - current element) exists in a hash set.

• If the complement exists, add the pair to the result. If not, add the current element to the hash set.

• Handle cases where the same element is used twice in a pair (e.g., target = 6, array = [3, 3]).

Implement a function to delete a node from a linked list at a specified position.

• Traverse the linked list to find the node at the specified position.

• Update the pointers of the previous and next nodes to skip the node to be deleted.

• Handle cases where the position is at the beginning or end of the linked list.

• Ensure to free the memory of the deleted node to avoid memory leaks.

Find the longest subsegment where at most one number can be changed to make it strictly increasing.

• Iterate through the array and keep track of the longest increasing subsegment with at most one change.

• If a number violates the increasing order, try changing it and check if the subsegment becomes strictly increasing.

• Update the length of the longest subsegment found so far.

• Return the length of the longest subsegment for each test case.

Rearrange array with zeros on the left and non-zeros on the right while maintaining original order.

• Iterate through the array from right to left, moving non-zero elements to the end of the array.

• Track the index where non-zero elements should be placed.

• Fill the beginning of the array with zeros and the rest with non-zero elements in their original order.

Simplify a polynomial expression by combining like terms and arranging them in descending order of degrees.

• Iterate through the coefficients and degrees arrays to combine like terms

• Create a new array to store the simplified polynomial in descending order of degrees

• Return the simplified polynomial array

Find and print all possible paths for a rat to reach the bottom-right corner of a maze.

• Create a recursive function to explore all possible paths in the maze.

• Keep track of the current path and mark visited cells.

• Return the paths as matrices with 1 for cells in the path and 0 for others.

The problem involves finding the diameter of a binary tree, which is the length of the longest path between any two end nodes in the tree.

• Traverse the tree to find the longest path between two nodes.

• Use recursion to calculate the diameter of the binary tree.

• Keep track of the maximum diameter found during traversal.

• Consider the height of the left and right subtrees to calculate the diameter.

• Example: For the input 1 2 3 4 -1 5 6 -1 7 -1 -1 -1 -1 -1 -1, the diameter of the binar...read more

Designing an application like Instagram involves creating a platform for sharing photos and videos with social networking features.

• Implement user profiles with the ability to upload, like, comment, and share photos/videos

• Develop a news feed algorithm to display content based on user preferences and interactions

• Include features like filters, hashtags, geotagging, and direct messaging

• Integrate push notifications for likes, comments, and new followers

• Ensure scalability and perfo...read more