Member Technical Staff 1 Interview Questions and Answers

Valid parenthesis time and space complexity and past projects

• Approaches for checking valid parenthesis include using a stack or recursion

• Time complexity for stack approach is O(n) and space complexity is O(n)

• Time complexity for recursion approach is O(2^n) and space complexity is O(n)

• Past projects may include developing algorithms for string manipulation or parsing

Recursively find the sum of digits in a given number

• Create a recursive function that takes in a number as input

• Base case: if the number is less than 10, return the number

• Recursive case: return the last digit of the number added to the result of calling the function with the number divided by 10

• Example: For input 123, the sum of digits would be 1 + 2 + 3 = 6

To find some of each level in a tree, traverse the tree level by level and sum the values at each level.

• Traverse the tree level by level using BFS (Breadth First Search)

• At each level, sum the values of the nodes

• Store the sum of each level in an array of strings

Find the longest increasing subsequence in an array

• Use dynamic programming to solve this problem efficiently

• Iterate through the array and keep track of the longest increasing subsequence ending at each index

• The final answer will be the maximum value in the longest increasing subsequence array

Efficiently search for an element in a sorted 2D matrix using binary search techniques.

• The matrix is sorted both row-wise and column-wise.

• Start from the top-right corner of the matrix.

• If the target is less than the current element, move left.

• If the target is greater, move down.

• Continue until the target is found or bounds are exceeded.

• Example: In a matrix [[1, 3, 5], [7, 9, 11], [12, 14, 16]], searching for 9 returns true.