Introduction

In this blog post, we'll share the most commonly asked coding interview questions at WeRide. 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: Longest Increasing Path in a Matrix

Given an m x n integers matrix, return the length of the longest increasing path in matrix. From each cell, you can either move in four directions: left, right, up, or down. You may not move diagonally or move outside the boundary (i.e., wrap-around is not allowed). Example 1: Input: matrix = [[9,9,4],[6,6,8],[2,1,1]] Output: 4 Explanation: The longest increasing path is [1, 2, 6, 9]. Example 2: Input: matrix = [[3,4,5],[3,2,6],[2,2,1]] Output: 4 Explanation: The longest increasing path is [3, 4, 5, 6]. Moving diagonally is not allowed. Example 3: Input: matrix = [[1]] Output: 1 Constraints: m == matrix.length n == matrix[i].length 1 <= m, n <= 200 0 <= matrix[i][j] <= 231 - 1

Topics: Array, Dynamic Programming, Depth-First Search, Breadth-First Search, Graph, Topological Sort, Memoization, Matrix