每日一练 | Data Scientist & Business Analyst & Leetcode 面试题 322

Day 222

Why is “Naive” Bayes naive?

SQL: Query the list of CITY names ending with vowels (a, e, i, o, u) from STATION. Your result cannot contain duplicates.

The STATION table is described as follows:

• Description:

• Suppose an array sorted in ascending order is rotated at some pivot unknown to you beforehand.

• (i.e., 0 1 2 4 5 6 7 might become 4 5 6 7 0 1 2).

• You are given a target value to search. If found in the array return its index, otherwise return -1.

• Input: 4 5 6 7 0 1 2, 5

• Output: 2

• Assumptions:

• You may assume no duplicate exists in the array.

Day 221 答案揭晓

What is Bayes’ Theorem? How is it useful in a machine learning context?

Bayes’ Theorem:

Bayes’ Theorem gives you the posterior probability of an event given what is known as prior knowledge.It’s expressed as the true positive rate of a condition sample divided by the sum of the false positive rate of the population and the true positive rate of a condition.

How is it useful:

Bayes’ Theorem is the basis behind a branch of machine learning that most notably includes the Naive Bayes classifier.

Reference:

https://betterexplained.com/articles/an-intuitive-and-short-explanation-of-bayes-theorem/

SQL: Query the list of CITY names starting with vowels (i.e., a, e, i, o, or u) from STATION. Your result cannot contain duplicates.

The STATION table is described as follows:

where LAT_N is the northern latitude and LONG_W is the western longitude.

Answer:

select CITY

from STATION

where CITY REGEXP '^[AEIOU]';

• Description:

• Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers.

• If such arrangement is not possible, it must rearrange it as the lowest possible order (ie, sorted in ascending order).

• The replacement must be in-place, do not allocate extra memory.

• Input: 1,2,3

• Output: 1,3,2