30+ Acoworlds Technology Interview Questions and Answers

Function to simulate dice roll with equal probability without using random function

• Use a toss function that returns either 0 or 1 with equal probability

• Call the toss function 3 times and convert the result to a binary number

• If the binary number is greater than 0 and less than or equal to 6, return it

• If the binary number is greater than 6, repeat the process

Given three sorted arrays, find common elements.

• Create three pointers to traverse each array

• Compare the elements at the pointers and move the pointer of the smallest element

• If all pointers point to the same element, add it to the result and move all pointers

• Repeat until any pointer reaches the end of its array

Function to determine the order of integers in an array.

• Check first and last element to determine if increasing or decreasing

• Check for inflection point to determine if order changes

• Return order type as string

Design a database schema for a movie site with user ratings and recommendations.

• Create tables for movies, users, ratings, and recommendations

• Use foreign keys to link tables

• Include columns for movie genre and user watch history

• Algorithm for recommendations can use user watch history and ratings to suggest similar movies

Measure 5 litres of water using 3 and 7 litre containers.

• Fill the 3 litre container completely

• Pour the water from the 3 litre container into the 7 litre container

• Fill the 3 litre container again and pour it into the 7 litre container until it is full

• The remaining water in the 3 litre container is 1 litre

• Empty the 7 litre container and pour the 1 litre water from the 3 litre container into it

• Fill the 3 litre container again and pour it into the 7 litre container

• The 7 litre con...read more

Left join returns all records from left table and matching records from right table. Full outer join returns all records from both tables.

• Left join is used to combine two tables based on a common column.

• In left join, all records from the left table are returned along with matching records from the right table.

• If there is no match in the right table, NULL values are returned.

• Example: SELECT * FROM table1 LEFT JOIN table2 ON table1.id = table2.id;

• Full outer join returns all rec...read more

Optimize images, minify code, reduce HTTP requests, use caching, and lazy loading.

• Optimize images using compression and appropriate file formats

• Minify code to reduce file size and improve load times

• Reduce HTTP requests by combining files and using sprites

• Use caching to store frequently accessed data locally

• Implement lazy loading to defer loading of non-critical resources

Magic functions are special methods in PHP that start with __. Autoloading is a way to automatically load classes.

• Magic functions are used to handle certain events in PHP, such as object creation or property access.

• Autoloading allows PHP to automatically load classes when they are needed, without requiring manual includes.

• Magic functions can be used in conjunction with autoloading to dynamically load classes or handle errors.

Function to check if two strings are anagram or not

• Create two character arrays from the strings

• Sort the arrays

• Compare the sorted arrays

Query to fetch duplicate email from table

• Use GROUP BY and HAVING clause to filter out duplicates

• SELECT email, COUNT(*) FROM table_name GROUP BY email HAVING COUNT(*) > 1;

• This will return all the duplicate emails in the table

The .on('click',function() is a more flexible method than .click(function())

• The .on() method can handle multiple events and selectors

• The .click() method can only handle one event and one selector

• The .on() method can also handle dynamically added elements

• The .click() method cannot handle dynamically added elements

Queue can be implemented using two stacks by maintaining the order of elements in the stacks.

• Create two stacks, let's call them stack1 and stack2

• When an element is enqueued, push it to stack1

• When an element is dequeued, pop all elements from stack1 and push them to stack2

• Pop the top element from stack2 and return it as the dequeued element

• If stack2 is empty, repeat step 3

• To get the front element of the queue, peek the top element of stack2

Check if a number is a power of 2 or not.

• A power of 2 has only one bit set in its binary representation.

• Use bitwise AND operator to check if the number is a power of 2.

• If n is a power of 2, then n & (n-1) will be 0.