每日一练 | Data Scientist & Business Analyst & Leetcode 面试题 353

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DS Interview Question

Talk about how K-D Tree improve the KNN.

BA Interview Question

R Programing: How many data structures does R language have?

LeetCode Question

Four Sum

Description: Given an array S of n integers, find three integers in S such that the sum is closest to a given number, target. Return the sum of the three integers. You may assume that each input would have exactly one solution.

Input: [2, 7, 11, 15]

Output: [0, 1]

Assumptions:  each input would have exactly one solution.

DS Interview Question & Answer

How do we choose the factor K?

Answer:

The small K will cause the results in a great variance, the larger K will make every points classified at the most probable class. So what we need to do is to set aside a part of the training data as a validation set, then change different numbers of K to see which one makes the best performance

BA Interview Question & Answer

R Programming question: two vectors X and Y are defined as follows X

What will be output of vector Z that is defined as

Z

Answer:

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 -