Digital Technology Intern Interview Questions and Answers

Maximize sum by selecting elements from array and removing adjacent elements.

• Select element 'i' and remove 'i-1' and 'i+1' from array during each operation.

• Continue until array is empty to maximize sum of selected elements.

• Focus on maximizing sum rather than printing results.

Given a number represented as a string, find the smallest number greater than the original with the same digits.

• Iterate from right to left to find the first digit that can be swapped with a smaller digit on its right.

• Swap this digit with the smallest digit on its right that is greater than it.

• Sort the digits to the right of the swapped digit in ascending order to get the smallest number.

• If no such number exists, return -1.

• Example: For S = '56789', the output should be '56798'...read more

Implement a queue using only stack data structure with predefined functions for FIFO operations.

• Use two stacks to simulate a queue - one for enqueue and one for dequeue operations.

• For enQueue operation, push elements onto the enqueue stack.

• For deQueue operation, if the dequeue stack is empty, transfer elements from enqueue stack to dequeue stack.

• For peek operation, return the top element of the dequeue stack.

• For isEmpty operation, check if both stacks are empty.

• Example: enQue...read more

Determine the minimum number of platforms needed at a railway station so that no train has to wait.

• Sort the arrival and departure times arrays in ascending order.

• Use two pointers to iterate through the arrays and keep track of the number of platforms needed.

• Increment the number of platforms needed when a train arrives and decrement when a train departs.

• Return the maximum number of platforms needed at any point.

• Example: For AT = [900, 940, 950] and DT = [910, 1200, 1120], the ...read more

Find the second largest element in an array of integers. Return -1 if second largest does not exist.

• Iterate through the array to find the largest and second largest elements.

• Handle cases where all elements are identical by returning -1.

• Consider edge cases like empty array or array with less than 2 elements.