Introduction

In this blog post, we'll share the most commonly asked coding interview questions at Cognizant. If you don't have months to study for your interviews, you can use AI tools like Chatmagic to generate solutions quickly and efficiently - helping you pass the interviews and get the job offer!

Problem #1: Count Subarrays of Length Three With a Condition

Given an integer array nums, return the number of subarrays of length 3 such that the sum of the first and third numbers equals exactly half of the second number. Example 1: Input: nums = [1,2,1,4,1] Output: 1 Explanation: Only the subarray [1,4,1] contains exactly 3 elements where the sum of the first and third numbers equals half the middle number. Example 2: Input: nums = [1,1,1] Output: 0 Explanation: [1,1,1] is the only subarray of length 3. However, its first and third numbers do not add to half the middle number. Constraints: 3 <= nums.length <= 100 -100 <= nums[i] <= 100

Topics: Array

Problem #2: Product Sales Analysis I

Table: Sales +-------------+-------+ | Column Name | Type | +-------------+-------+ | sale_id | int | | product_id | int | | year | int | | quantity | int | | price | int | +-------------+-------+ (sale_id, year) is the primary key (combination of columns with unique values) of this table. product_id is a foreign key (reference column) to Product table. Each row of this table shows a sale on the product product_id in a certain year. Note that the price is per unit. Table: Product +--------------+---------+ | Column Name | Type | +--------------+---------+ | product_id | int | | product_name | varchar | +--------------+---------+ product_id is the primary key (column with unique values) of this table. Each row of this table indicates the product name of each product. Write a solution to report the product_name, year, and price for each sale_id in the Sales table. Return the resulting table in any order. The result format is in the following example. Example 1: Input: Sales table: +---------+------------+------+----------+-------+ | sale_id | product_id | year | quantity | price | +---------+------------+------+----------+-------+ | 1 | 100 | 2008 | 10 | 5000 | | 2 | 100 | 2009 | 12 | 5000 | | 7 | 200 | 2011 | 15 | 9000 | +---------+------------+------+----------+-------+ Product table: +------------+--------------+ | product_id | product_name | +------------+--------------+ | 100 | Nokia | | 200 | Apple | | 300 | Samsung | +------------+--------------+ Output: +--------------+-------+-------+ | product_name | year | price | +--------------+-------+-------+ | Nokia | 2008 | 5000 | | Nokia | 2009 | 5000 | | Apple | 2011 | 9000 | +--------------+-------+-------+ Explanation: From sale_id = 1, we can conclude that Nokia was sold for 5000 in the year 2008. From sale_id = 2, we can conclude that Nokia was sold for 5000 in the year 2009. From sale_id = 7, we can conclude that Apple was sold for 9000 in the year 2011.

Topics: Database

Problem #3: Fibonacci Number

The Fibonacci numbers, commonly denoted F(n) form a sequence, called the Fibonacci sequence, such that each number is the sum of the two preceding ones, starting from 0 and 1. That is, F(0) = 0, F(1) = 1 F(n) = F(n - 1) + F(n - 2), for n > 1. Given n, calculate F(n). Example 1: Input: n = 2 Output: 1 Explanation: F(2) = F(1) + F(0) = 1 + 0 = 1. Example 2: Input: n = 3 Output: 2 Explanation: F(3) = F(2) + F(1) = 1 + 1 = 2. Example 3: Input: n = 4 Output: 3 Explanation: F(4) = F(3) + F(2) = 2 + 1 = 3. Constraints: 0 <= n <= 30

Topics: Math, Dynamic Programming, Recursion, Memoization