10+ Efacec Interview Questions and Answers

Use a max heap to keep track of the K largest elements in a continuous stream of integers.

• Create a max heap of size K to store the K largest elements.

• For each new element in the stream, compare it with the root of the max heap. If it is larger, replace the root with the new element and heapify.

• At any point, the root of the max heap will be the Kth largest element in the stream.

Use sliding window technique to find minimum window in s containing all characters of t.

• Use two pointers to create a window in s

• Move the right pointer to expand the window until all characters of t are found

• Move the left pointer to shrink the window while maintaining all characters of t

• Update minimum window size as you iterate through s

The minimum number of coins required to express a given amount of money is calculated using a dynamic programming approach.

• Use dynamic programming to calculate the minimum number of coins required for each amount from 1 to the given amount.

• Start with the base case of 0 coins required for amount 0, then iterate through each coin type to calculate the minimum coins required for each amount.

• Choose the minimum of the current minimum coins required and the minimum coins required f...read more

Program to find longest consecutive sequence and length of longest path in a binary tree.

• Traverse the binary tree using depth-first search (DFS)

• Keep track of the current consecutive sequence length and the longest consecutive sequence found so far

• Update the length of the longest path as you traverse the tree

Program to find lowest common ancestor of two nodes in a binary tree with unique values.

• Start from the root and traverse the tree to find the paths from root to the two nodes.

• Compare the paths to find the lowest common ancestor node.

• Use recursion to traverse the tree efficiently.

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

Return the next lexicographically greater permutation of a given sequence or return it in ascending order if not possible.

• Use the concept of lexicographic ordering to find the next permutation.

• If the sequence is already in descending order, return it in ascending order.

• Examples: ['a', 'b', 'c'] -> ['a', 'c', 'b'], ['3', '2', '1'] -> ['1', '2', '3']

Convert a set of integers to Roman numerals

• Create a function that takes an integer array as input

• Use a loop to iterate through each integer and convert it to Roman numeral

• Implement a mapping of integers to Roman numerals for conversion

• Return an array of strings containing the Roman numeral equivalents

Find all palindromic decompositions of a given string s.

• Iterate through all possible substrings and check if they are palindromes.

• Use backtracking to generate all possible decompositions.

• Return the list of palindromic decompositions.

Autocomplete feature for a search engine

• 1. Display suggestions as user types in the search bar

• 2. Suggestions should be based on popular searches or previous searches

• 3. Allow users to select a suggestion to complete their search

• 4. Update suggestions in real-time as the user continues typing

A customer relationship management platform for Comcast would focus on personalized customer interactions and efficient issue resolution.

• Implement a centralized database to store customer information and interaction history.

• Integrate communication channels such as phone, email, and chat for seamless customer support.

• Utilize data analytics to track customer behavior and preferences for targeted marketing campaigns.

• Automate processes for issue resolution and follow-up to improv...read more

A ticketing management system for a theatre to streamline ticket sales and seat allocation.

• Create an online platform for customers to purchase tickets

• Implement a seating chart to allow customers to select their seats

• Include options for different ticket types (e.g. VIP, standard, student)

• Generate electronic tickets for customers to present at the theatre entrance

• Integrate payment processing for secure transactions