每日一练 | Data Scientist & Business Analyst & Leetcode 面试题 247
从6月15日起，数据应用学院将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 147
DS Interview Questions
How do we choose the factor K?
BA Interview Questions
R Programing: How many data structures does R language have?
Leetcode Questions
Description:
Given a set of candidate numbers © (without duplicates) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.
The same repeated number may be chosen from C unlimited number of times.
Input: [2, 3, 6, 7]
Output: [[7], [2, 2, 3]]
Assumptions:
without duplicates
All numbers (including target) will be positive integers.
欲知答案如何？请见下期分解！
Day 146 答案揭晓
DS Interview Questions
How does the KNN algorithm work?
KNN is a supervised machine learning algorithm, basically it works based on minimum distance from the query instance to the training samples to determine the K-nearest neighbors to be the prediction of the query instance. It can be used on both classification and regression problem.
BA Interview Questions
R Programming question: two vectors X and Y are defined as follows X <- c(3,2,4) and Y <- c(1,2). What will be output of vector Z that is defined as Z <- X*Y
in R language when the vectors have different lengths, the multiplication begins with the smaller vector and continues till all the elements in the larger vector has been multiplied
The output of the above code will be -
Z <- (3,4,4)
Leetcode Questions
Description:
The count-and-say sequence is the sequence of integers with the first five terms as following:
1 is read off as “one 1” or 11.
11 is read off as “two 1s” or 21.
21 is read off as “one 2, then one 1” or 1211.
Given an integer n, generate the nth term of the count-and-say sequence.
Note: Each term of the sequence of integers will be represented as a string.
Input: 4
Output: “1211”
点击“阅读原文”查看数据应用学院核心课程