Ozon Coding Interview Questions

Valid Parentheses

Given a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.

Squares of a Sorted Array

Given an integer array nums sorted in non-decreasing order, return an array of the squares of each number sorted in non-decreasing order.

Merge Intervals

Given an array of intervals where intervals[i] = [starti, endi], merge all overlapping intervals, and return an array of the non-overlapping intervals that cove...

Department Top Three Salaries

Table: Employee

Monotonic Array

An array is monotonic if it is either monotone increasing or monotone decreasing.

Two Sum

Given an array of integers nums and an integer target, return the indices of the two numbers that add up to target.

First Unique Character in a String

Given a string s, find the first non-repeating character in it and return its index. If it does not exist, return -1.

Invert Binary Tree

Given the root of a binary tree, invert the tree, and return its root.

Department Highest Salary

Table: Employee

Longest Substring Without Repeating Characters

Given a string s, find the length of the longest substring without duplicate characters.

Best Time to Buy and Sell Stock

You are given an array prices where prices[i] is the price of a given stock on the ith day.

Reverse Linked List

Given the head of a singly linked list, reverse the list, and return the reversed list.

Decode String

Given an encoded string, return its decoded string.

Move Zeroes

Given an integer array nums, move all 0's to the end of it while maintaining the relative order of the non-zero elements.