Introduction

In this blog post, we'll share the most commonly asked coding interview questions at Twilio. 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: Maximize Greatness of an Array

You are given a 0-indexed integer array nums. You are allowed to permute nums into a new array perm of your choosing. We define the greatness of nums be the number of indices 0 <= i < nums.length for which perm[i] > nums[i]. Return the maximum possible greatness you can achieve after permuting nums. Example 1: Input: nums = [1,3,5,2,1,3,1] Output: 4 Explanation: One of the optimal rearrangements is perm = [2,5,1,3,3,1,1]. At indices = 0, 1, 3, and 4, perm[i] > nums[i]. Hence, we return 4. Example 2: Input: nums = [1,2,3,4] Output: 3 Explanation: We can prove the optimal perm is [2,3,4,1]. At indices = 0, 1, and 2, perm[i] > nums[i]. Hence, we return 3. Constraints: 1 <= nums.length <= 105 0 <= nums[i] <= 109

Topics: Array, Two Pointers, Greedy, Sorting

Problem #2: Ways to Make a Fair Array

You are given an integer array nums. You can choose exactly one index (0-indexed) and remove the element. Notice that the index of the elements may change after the removal. For example, if nums = [6,1,7,4,1]: Choosing to remove index 1 results in nums = [6,7,4,1]. Choosing to remove index 2 results in nums = [6,1,4,1]. Choosing to remove index 4 results in nums = [6,1,7,4]. An array is fair if the sum of the odd-indexed values equals the sum of the even-indexed values. Return the number of indices that you could choose such that after the removal, nums is fair. Example 1: Input: nums = [2,1,6,4] Output: 1 Explanation: Remove index 0: [1,6,4] -> Even sum: 1 + 4 = 5. Odd sum: 6. Not fair. Remove index 1: [2,6,4] -> Even sum: 2 + 4 = 6. Odd sum: 6. Fair. Remove index 2: [2,1,4] -> Even sum: 2 + 4 = 6. Odd sum: 1. Not fair. Remove index 3: [2,1,6] -> Even sum: 2 + 6 = 8. Odd sum: 1. Not fair. There is 1 index that you can remove to make nums fair. Example 2: Input: nums = [1,1,1] Output: 3 Explanation: You can remove any index and the remaining array is fair. Example 3: Input: nums = [1,2,3] Output: 0 Explanation: You cannot make a fair array after removing any index. Constraints: 1 <= nums.length <= 105 1 <= nums[i] <= 104

Topics: Array, Prefix Sum