Introduction

In this blog post, we'll share the most commonly asked coding interview questions at Revolut. 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: Longest Common Prefix

Write a function to find the longest common prefix string amongst an array of strings. If there is no common prefix, return an empty string "". Example 1: Input: strs = ["flower","flow","flight"] Output: "fl" Example 2: Input: strs = ["dog","racecar","car"] Output: "" Explanation: There is no common prefix among the input strings. Constraints: 1 <= strs.length <= 200 0 <= strs[i].length <= 200 strs[i] consists of only lowercase English letters if it is non-empty.

Topics: String, Trie

Problem #2: Binary Tree Paths

Given the root of a binary tree, return all root-to-leaf paths in any order. A leaf is a node with no children. Example 1: Input: root = [1,2,3,null,5] Output: ["1->2->5","1->3"] Example 2: Input: root = [1] Output: ["1"] Constraints: The number of nodes in the tree is in the range [1, 100]. -100 <= Node.val <= 100

Topics: String, Backtracking, Tree, Depth-First Search, Binary Tree

Problem #3: Reverse Linked List II

Given the head of a singly linked list and two integers left and right where left <= right, reverse the nodes of the list from position left to position right, and return the reversed list. Example 1: Input: head = [1,2,3,4,5], left = 2, right = 4 Output: [1,4,3,2,5] Example 2: Input: head = [5], left = 1, right = 1 Output: [5] Constraints: The number of nodes in the list is n. 1 <= n <= 500 -500 <= Node.val <= 500 1 <= left <= right <= n Follow up: Could you do it in one pass?

Topics: Linked List

Problem #4: Perfect Squares

Given an integer n, return the least number of perfect square numbers that sum to n. A perfect square is an integer that is the square of an integer; in other words, it is the product of some integer with itself. For example, 1, 4, 9, and 16 are perfect squares while 3 and 11 are not. Example 1: Input: n = 12 Output: 3 Explanation: 12 = 4 + 4 + 4. Example 2: Input: n = 13 Output: 2 Explanation: 13 = 4 + 9. Constraints: 1 <= n <= 104

Topics: Math, Dynamic Programming, Breadth-First Search