每日一练 | Data Scientist & Business Analyst & Leetcode 面试题 282

大数据应用 · 公众号 · 大数据 · 2018-01-26 10:00

正文

自2017年6月15日起，数据应用学院与你一起温习数据科学（DS）和商业分析（BA）领域常见的面试问题。从2017年10月4号起，每天再为大家分享一道Leetcode算法题。

希望积极寻求相关领域工作的你每天关注我们的问题并且与我们一起思考，我们将会在第二天给出答案。

Day 182

DS Interview Questions

Explain what a long-tailed distribution is and provide three examples of relevant phenomena that have long tails. Why are they important in classification and regression problems?

BA Interview Questions

What is Gross Rating Points (GRPs), Cost per Point (CPP), and Impressions?

Leetcode Questions

Description:

Given a sorted linked list, delete all duplicates such that each element appear only once

Input: 1 → 1 → 2

Output: 1 → 2

欲知答案如何？请见下期分解！

Day 181 答案揭晓

DS Interview Questions

What challenges does a Data Scientist usually face?

Handling data from multiple sources: The value of the data mined increases when a data scientist is able to reach across the expanse of the data landscape and access data from multiple platforms and data sources.
Predicting Outcomes from the data: The final result is not necessarily the same as predicting data. Results might be unexpected even when datasets are given.
Communicating with people: Understanding the data is not enough for a Data Scientist. It is also important to make it presentable to the people as well.

BA Interview Questions

What is Rating, Average Persons and Spot?

Rating

Rating is the percentage (0 to 100) of the Media Market that will likely be exposed to your advertisement. Rating is an estimate based on past performance often sourced from surveys.

Average Persons

Average Persons is the number of people that, on average, will be exposed to each Spot. Average Persons is calculated by multiplying Population by Rating then dividing by 100.

Spot

A Spot is a single broadcast of an advertisement. Typically, an advertising placement includes multiple spots.

Reference:

http://www.bionic-ads.com/2016/03/reach-frequency-ratings-grps-impressions-cpp-and-cpm-in-advertising/

Leetcode Questions

Description:

Given an array and a value, remove all instances of that value in place and return the new length.
Do not allocate extra space for another array, you must do this in place with constant memory.
The order of elements can be changed. It doesn’t matter what you leave beyond the new length.

Input: [3,2,2,3]

Output: 2

Assumptions: