Blackrock Software Developer Interview Questions and Answers

Find the greatest common divisor (GCD) of two given numbers 'X' and 'Y'.

• Iterate from 1 to the minimum of X and Y, check if both X and Y are divisible by the current number, update GCD if true

• Use Euclidean algorithm to find GCD: GCD(X, Y) = GCD(Y, X % Y)

• If one of the numbers is 0, the other number is the GCD

• Handle edge cases like when one of the numbers is 0 or negative

Given 'N' stars, construct a triangle with maximum height using 'i' stars in 'i'th level.

• Calculate the maximum height of the triangle using the formula: height = floor((-1 + sqrt(1 + 8 * N)) / 2)

• Iterate through each test case and calculate the maximum height for each 'N'.

• Output the maximum height for each test case.

Find the shortest distance between two nodes in a Binary Search Tree.

• Traverse the BST to find the paths from the root to both nodes.

• Compare the paths to find the common ancestor node.

• Calculate the distance by adding the lengths of the paths from the common ancestor to both nodes.

• Return the shortest distance as the result.

Find all the bridges in an undirected graph.

• Use Tarjan's algorithm to find bridges in the graph.

• A bridge is an edge whose removal increases the number of connected components.

• Check for bridges by removing each edge and running a DFS to see if the graph is still connected.

Convert a binary string to its decimal equivalent integer.

• Iterate through the binary string from right to left, multiplying each digit by 2 raised to the power of its position.

• Add the results of the multiplication to get the decimal equivalent.

• Ensure the binary string consists only of '0' and '1' characters.

• Handle multiple test cases by repeating the conversion process for each case.