10+ Urban Company Software Developer Interview Questions and Answers

Determine the minimum number of conference rooms needed to schedule meetings without overlap.

• Sort the meetings by start time.

• Iterate through the meetings and keep track of the rooms in use.

• If a meeting starts after another ends, it can reuse the same room.

• If a meeting starts before another ends, a new room is needed.

• Return the maximum number of rooms in use at any point.

Find an integer Y such that XOR operation with X yields maximum value within given constraints.

• Iterate from the most significant bit to find the highest bit that can be toggled to maximize XOR value.

• To maximize XOR value, toggle the highest bit of X to 0 and all lower bits to 1.

• Ensure the final Y does not exceed (2^61) - 1.

• Example: For X = 3, the highest bit to toggle is at position 61, so Y = 2305843009213693950.

• Example: For X = 7, the highest bit to toggle is at position 60...read more

Generate all possible non-empty subsets of an array of distinct integers.

• Use recursion to generate all subsets by including or excluding each element in the array.

• Maintain a current subset and add it to the result when reaching the end of the array.

• Ensure elements within each subset are in increasing order.

• Handle the input and output format as specified in the question.

Remove K elements from a non-decreasing array to minimize the maximum difference between adjacent elements.

• Sort the array in non-decreasing order.

• Iterate through the array and calculate the difference between adjacent elements.

• Remove elements to minimize the maximum difference.

• Return the minimized maximum difference.

Implement a function to find the index of the first occurrence of one string within another string.

• Iterate through the second string and check if a substring of the same length as the first string matches the first string.

• Return the index of the first occurrence of the first string within the second string, or -1 if not found.

• Handle edge cases like empty strings or when the first string is longer than the second string.

Count occurrences of a number in a sorted array efficiently.

• Use binary search to find the first and last occurrence of the target number in the array.

• Calculate the count of occurrences by subtracting the indices of the last and first occurrences.

• Handle cases where the target number is not found in the array.

• Time complexity: O(log(N)), Space complexity: O(1).

Calculate the number of distinct subsequences in a string with possible duplicates.

• Use dynamic programming to keep track of the count of distinct subsequences for each character in the string.

• Consider the cases where the current character is included or excluded in the subsequence.

• Handle duplicates by considering the previous occurrence of the character.

• Return the count of distinct subsequences modulo 10^9 + 7.

Search for integers in a rotated sorted array efficiently.

• Implement binary search to find the target integer in the rotated array.

• Handle the rotation by checking which side of the array is sorted before performing binary search.

• Return the index of the target integer if found, else return -1.

• Time complexity of O(logN) is required for each query.

Find the minimum time required to rot all fresh oranges in a grid.

• Use Breadth First Search (BFS) to simulate the rotting process

• Track the time taken to rot all oranges and return -1 if any fresh oranges remain

• Handle edge cases such as no fresh oranges or all oranges already rotten

• Consider using a queue to efficiently process neighboring oranges

Yes, the cloning of a linked list with random pointer can be accomplished without utilizing extra space.

• Use a hashmap to store the mapping between original nodes and cloned nodes.

• Iterate through the original linked list to create the cloned linked list by mapping the random pointers using the hashmap.

• Time complexity of this approach is O(N) where N is the number of nodes in the linked list.

Find the length of the shortest path visiting all nodes in a connected undirected unweighted graph.

• Use Breadth First Search (BFS) to find the shortest path that visits all nodes at least once.

• Maintain a bitmask to keep track of visited nodes and their states.

• Consider all possible permutations of nodes to find the shortest path length.

Find the row with the maximum number of 1's in a sorted 2D matrix.

• Iterate through each row of the matrix and count the number of 1's in each row.

• Keep track of the row index with the maximum number of 1's seen so far.

• Return the index of the row with the maximum number of 1's.

• If multiple rows have the same number of 1's, return the row with the smallest index.

Check if the third string contains all characters from the first and second strings in any order.

• Create a frequency map for characters in the first and second strings.

• Check if all characters in the third string are present in the frequency map.

• Ensure the count of characters in the third string matches the count in the frequency map.

• Return 'YES' if all conditions are met, otherwise return 'NO'.

Implement a solution to find the maximum profit from buying and selling stocks with at most 2 transactions.

• Use dynamic programming to keep track of maximum profit at each day with 0, 1, or 2 transactions.

• Consider the possibility of splitting the transactions into two separate parts.

• Calculate the maximum profit by iterating through the prices array and updating the maximum profit accordingly.

A thread is a lightweight process that can run concurrently with other threads within the same process.

• Threads allow for parallel execution of tasks within a single process.

• Threads share the same memory space and resources of the process they belong to.

• Threads can communicate with each other through shared memory or message passing.

• Examples: Java threads, POSIX threads (pthreads) in C/C++.

Binary search is a divide and conquer algorithm that efficiently finds a target value in a sorted array.

• Divide the array in half and compare the target value with the middle element

• If the target is less than the middle element, search the left half. If greater, search the right half

• Repeat the process until the target is found or the subarray is empty