Unthinkable Solutions Software Developer Interview Questions and Answers for Freshers

The task is to find the duplicate element in an array of integers.

• Iterate through the array and keep track of the frequency of each element using a hash map.

• Return the element with a frequency greater than 1.

• Alternatively, sort the array and check for adjacent elements with the same value.

The question asks to find the total amount of rainwater that can be trapped in the given elevation map.

• Iterate through the array and find the maximum height on the left and right side of each bar.

• Calculate the amount of water that can be trapped on each bar by subtracting its height from the minimum of the maximum heights on both sides.

• Sum up the amount of water trapped on each bar to get the total amount of rainwater trapped.

The given string needs to be reversed word wise, keeping the individual words intact.

• Split the string into an array of words using a space as the delimiter.

• Reverse the array of words.

• Join the reversed array of words using a space as the separator to form the final reversed string.

The task is to sort an array of 0s, 1s, and 2s in increasing order.

• Use a three-pointer approach to partition the array into three sections: 0s, 1s, and 2s.

• Initialize three pointers: low, mid, and high. low points to the start of the array, mid points to the current element being processed, and high points to the end of the array.

• While mid <= high, perform the following checks: if arr[mid] == 0, swap arr[low] and arr[mid], increment low and mid. If arr[mid] == 1, increment mid...read more

The task is to find the second largest element in an array of integers.

• Iterate through the array and keep track of the largest and second largest elements.

• Initialize the largest and second largest variables with the first two elements of the array.

• Compare each element with the largest and second largest variables and update them accordingly.

• Return the second largest element at the end.

The question asks whether it is possible to sort an array by choosing a continuous subarray and reversing it.

• Check if the array is already sorted. If yes, return true.

• Find the first and last elements of the subarray that needs to be reversed.

• Check if the subarray is in non-decreasing order. If yes, return true.

• Check if the elements after the subarray are in non-increasing order. If yes, return true.

• Otherwise, return false.

Design a data structure to efficiently find the kth largest number in a stream of numbers.

• Implement a data structure that can store incoming numbers and efficiently retrieve the kth largest number.

• Support addition of numbers and retrieval of the kth largest number.

• Use a priority queue or heap data structure to maintain the k largest numbers in the stream.

• Handle queries of adding numbers and retrieving the kth largest number.

• Ensure the system can handle an indefinite length of...read more

Given a Binary Search Tree, determine if a node with a given integer exists.

• Traverse the BST in a way that compares the current node's data with the given integer 'X'.

• If the current node's data is equal to 'X', return True.

• If the current node's data is less than 'X', move to the right subtree; if greater, move to the left subtree.

• Repeat this process until a match is found or the end of the tree is reached.