McKinney Chapter 2 - Practice Blank

FINA 6333 for Spring 2024

Author

Richard Herron

1 Announcements

2 Practice

2.1 Extract the year, month, and day from an integer 8-digit date (i.e., YYYYMMDD format) using `//` (integer division) and `%` (modulo division).

Try 20080915.

2.2 Use your answer above to write a function `date` that accepts an integer 8-digit date argument and returns a tuple of the year, month, and date (e.g., `return (year, month, date)`).

2.3 Rewrite `date` to accept an 8-digit date as an integer or string.

2.4 Finally, rewrite `date` to accept a list of 8-digit dates as integers or strings.

Return a list of tuples of year, month, and date.

2.5 Write a for loop that prints the squares of integers from 1 to 10.

2.6 Write a for loop that prints the squares of even integers from 1 to 10.

2.7 Write a for loop that sums the squares of integers from 1 to 10.

2.8 Write a for loop that sums the squares of integers from 1 to 10 but stops before the sum exceeds 50.

2.9 FizzBuzz

Write a for loop that prints the numbers from 1 to 100. For multiples of three print “Fizz” instead of the number. For multiples of five print “Buzz”. For numbers that are multiples of both three and five print “FizzBuzz”. More here.

2.10 Use ternary expressions to make your FizzBuzz code more compact.

2.11 Triangle

Write a function triangle that accepts a positive integer \(N\) and prints a numerical triangle of height \(N-1\). For example, triangle(N=6) should print:

2.12 Two Sum

Write a function two_sum that does the following.

Given an array of integers nums and an integer target, return the indices of the two numbers that add up to target.

You may assume that each input would have exactly one solution, and you may not use the same element twice.

You can return the answer in any order.

Here are some examples:

Example 1:

Input: nums = [2,7,11,15], target = 9
Output: [0,1]
Explanation: Because nums[0] + nums[1] == 9, we return [0, 1].

Example 2:

Input: nums = [3,2,4], target = 6
Output: [1,2]

Example 3:

Input: nums = [3,3], target = 6
Output: [0,1]

I saw this question on LeetCode.

2.13 Best Time

Write a function best_time that solves the following.

You are given an array prices where prices[i] is the price of a given stock on the \(i^{th}\) day.

You want to maximize your profit by choosing a single day to buy one stock and choosing a different day in the future to sell that stock.

Return the maximum profit you can achieve from this transaction. If you cannot achieve any profit, return 0.