Buyhatke Interview Questions and Answers

Given a directional string representing a route to a friend's house in an infinite grid, find the shortest lexicographically smallest route to reach the destination.

• Iterate through the directional string and keep track of the movements in each direction (E, W, N, S).

• Calculate the final position based on the movements and find the shortest lexicographically smallest route to reach that position.

• Consider the constraints and optimize the solution to handle large inputs efficient...read more

Yes, the 0/1 Knapsack problem can be solved using dynamic programming with a space complexity of not more than O(W).

• Use a 1D array to store the maximum value that can be stolen for each weight capacity from 0 to W.

• Iterate through each item and update the array based on whether including the item would increase the total value.

• The final value in the array at index W will be the maximum value that can be stolen.

Calculate the time in minutes required to completely burn a binary tree starting from a given node.

• Start burning from the given node and spread fire to adjacent nodes each minute

• Track the time taken for each node to burn completely

• Return the maximum time taken to burn the entire tree

LCA of a binary tree is the lowest common ancestor of two nodes in the tree.

• Traverse the tree from the root node to find the paths from root to the two given nodes.

• Compare the paths to find the last common node, which is the LCA.

• Use recursion to solve the problem efficiently.

• Handle edge cases like if one of the nodes is the ancestor of the other.

Swift was chosen for its performance, native iOS support, and better integration with Apple's ecosystem.

• Swift offers better performance compared to React Native due to its native code execution.

• Swift provides seamless integration with Apple's ecosystem, allowing for better utilization of iOS features.

• Swift is the preferred choice for developing iOS apps as it is the native language for iOS development.

• React Native may have limitations in accessing certain iOS features or APIs...read more

Observable in Swift is a property wrapper that allows for automatic notifications when the value changes.

• Observable is a property wrapper introduced in Swift 5.1.

• It can be used with any property that needs to be observed for changes.

• When the value of the property changes, any views using that property will be automatically updated.

• Example: @Published var score: Int = 0

Depth first search in tree is implemented using recursion to explore each branch fully before moving to the next.

• Start at the root node and recursively visit each child node before moving to the next sibling node.

• Use a stack to keep track of nodes to visit, pushing children onto the stack before siblings.

• Base case is when the current node is null or a leaf node, then backtrack to the parent node.