10+ Datamatics Global Services Interview Questions and Answers

Construct the largest number by concatenating positive integers in the array exactly once.

• Sort the array of integers in a way that the concatenation of the numbers forms the largest possible number.

• Use a custom comparator function to sort the numbers based on their concatenated values.

• Join the sorted array elements to form the final largest number.

The task is to find the length of the longest palindromic subsequence in a given string.

• A subsequence is a sequence generated from a string after deleting some or no characters of the string without changing the order of the remaining string characters.

• A string is said to be palindrome if the reverse of the string is the same as the actual string.

• Find the longest palindromic subsequence by considering all possible subsequences of the given string.

• Use dynamic programming to ef...read more

The task is to check if one string can be converted into another string by cyclically rotating it to the right any number of times.

• Iterate through each character of the first string and check if it matches the corresponding character in the second string after a certain number of cyclic rotations.

• If all characters match for any number of cyclic rotations, then the first string can be converted into the second string.

• Use modulo arithmetic to handle cyclic rotations efficiently...read more

Implement a cache with insert, update, and retrieve operations, returning results of retrieve operations in order.

• Create a cache data structure with specified size 'N'.

• Implement insert and update operations based on the given criteria.

• For retrieve operation, return the value associated with the 'U_ID' if present, else return -1.

• Handle cases where the cache is full and least frequently used items need to be removed.

• Return the results of all retrieve operations in the order the...read more

Count the number of longest increasing subsequences in an integer array.

• Identify the longest increasing subsequences in the array

• Count the number of such subsequences

• Consider the constraints while implementing the solution

• Examples: For input [50, 3, 90, 60, 80], the output is 2

The task is to find the next greater element for each element in an array.

• Iterate through the array from right to left

• Use a stack to keep track of the elements

• For each element, pop elements from the stack until a greater element is found or the stack is empty

• If a greater element is found, it is the next greater element for the current element

• If the stack becomes empty, there is no greater element to the right

• Store the next greater element for each element in a result array

The task is to merge two sorted linked lists into a single sorted linked list.

• Create a new linked list to store the merged list

• Compare the values of the nodes from both lists and add the smaller value to the new list

• Move the pointer of the list with the smaller value to the next node

• Repeat the comparison and addition until one of the lists is empty

• Add the remaining nodes from the non-empty list to the new list

• Return the head of the new list

Find the sum of the subarray with the maximum sum among all subarrays in a given array.

• Iterate through the array and keep track of the maximum sum subarray seen so far.

• Use Kadane's algorithm to efficiently find the maximum subarray sum.

• Handle cases where all elements are negative by returning the maximum element in the array.

• Consider the sum of an empty subarray as 0.

Implement a Least Recently Used (LRU) cache data structure with get and put operations.

• Use a combination of a hashmap and a doubly linked list to efficiently implement the LRU cache.

• Keep track of the least recently used item and remove it when the cache reaches its capacity.

• Update the position of an item in the cache whenever it is accessed or updated.

• Ensure constant time complexity for both get and put operations by using the hashmap for quick lookups.

• Handle edge cases such ...read more

Given an array of words, find the shortest unique prefix for each word.

• Create a Trie data structure to efficiently store and search for prefixes.

• Traverse the Trie to find the shortest unique prefix for each word.

• Return the list of shortest unique prefixes for all words.

Given a phone number, generate all possible words by mapping digits to letters on a T9 keypad.

• Create a mapping of digits to letters on a T9 keypad

• Use recursion to generate all possible combinations of letters for the given phone number

• Sort the resulting strings in lexicographical order