Google Frontend Engineer Interview Questions

In Google Photos, users can share albums with friends and family. You are tasked with optimizing the album sharing process to ensure maximum unique views within a minimum number of clicks.Problem Statement: Given two sorted arrays views1 and views2 representing the number of times two different albums have been viewed, implement a function maxUniqueViews(views1: number[], views2: number[]): number to return the maximum unique views a user can get by sharing the albums from both lists.- Example 1:
Input: views1 = [1, 3, 5], views2 = [2, 4, 6]
Output: 6
Explanation: All views are unique, hence 1 + 2 + 3. The unique views = 1, 3, 2, 4, 5, 6.- Example 2:
Input: views1 = [1, 2, 3], views2 = [3, 4, 5]
Output: 5
Explanation: The common view 3 counts only once. The unique views = 1, 2, 4, 5.Constraints:
- 1 <= views1.length, views2.length <= 10^5
- 1 <= views1[i], views2[j] <= 10^9

Google Ads requires an efficient method to determine the maximum exposure of ads based on a given window of time. You need to calculate the maximum number of ads that can be displayed within a specified duration while ensuring a minimum time gap between the same ads.Problem Statement: Given an integer array ads representing the timestamps of ads being displayed, and an integer minGap representing the minimum time gap required between the same ad displays, write a function maxAdsDisplayed(ads: number[], minGap: number): number that returns the maximum number of ads that can be displayed following this rule.- Example 1:
Input: ads = [1, 2, 3, 4, 5, 6], minGap = 2
Output: 4
Explanation: Ads can be displayed at timestamps 1, 3, 5 and 6, skipping timestamps 2 and 4 to respect the gap.- Example 2:
Input: ads = [1, 1, 1, 3, 5], minGap = 2
Output: 3
Explanation: Ads can be displayed at timestamps 1 (first), 3 and 5, respecting the minimum gap of 2.Constraints:
- 1 <= ads.length <= 10^5
- 1 <= ads[i] <= 10^9
- 1 <= minGap <= 10^6

Google Maps needs an efficient way to handle client-side routing for various map views. Your task is to design a class-based router that can manage routes based on the current path and dynamically load components.Problem Statement: Implement a class Router that manages routes for a map application and has the following methods:
- addRoute(path: string, component: any): void: Adds a new route mapping path to a component.
- navigate(path: string): void: Navigates to the specified path and loads the associated component.
- getCurrentComponent(): any: Returns the component of the current route.Example 1:
const router = new Router();
router.addRoute('/home', HomeComponent);
router.addRoute('/about', AboutComponent);
router.navigate('/home');
console.log(router.getCurrentComponent()); // HomeComponent exampleConstraints:
- The path will always be a string in the format of /[a-zA-Z]+.
- The component can be any function or class that should be rendered for that route.

As part of Google Search Services, you need to optimize data retrieval by implementing an LRU (Least Recently Used) Cache. This cache will store recently accessed search queries and their results, helping to reduce the load on Google's servers and speed up user interactions.Problem Statement: Design and implement a data structure for an LRU Cache that supports the following operations:
- get(key: number): number: Retrieves the value of the key if the key exists in the cache. Otherwise, returns -1.
- put(key: number, value: number): void: Updates the value of the key if the key exists. If the key does not exist, add the key-value pair to the cache. If the cache reaches its capacity, it should invalidate the least recently used item before inserting the new item.Example 1:
LRUCache cache = new LRUCache(2);
cache.put(1, 1);
cache.put(2, 2);
cache.get(1); // returns 1
cache.put(3, 3); // evicts key 2
cache.get(2); // returns -1 (not found)Constraints:
- capacity of the cache is between 1 and 3000.
- All keys and values are positive integers.