Question

Write a program that uses the comparison capabilities introduced in this chapter to alphabetize a series of animal names. Only uppercase letters should be used for the comparisons.

Short answer

Use the `sorted()` function with uppercase names to alphabetize the list.

Step-by-step solution

Create a list of animal names

First, create a list of animal names that you need to alphabetize. Make sure all animals have uppercase letters for consistency in comparison. Example: `['TIGER', 'GIRAFFE', 'DOG', 'CAT', 'ELEPHANT']`. This will enable comparisons without worrying about case sensitivity.

Define a comparison function

Define a function to compare two strings. While built-in capabilities exist, understand that under the hood, you compare using Unicode points. Here, we will use Python's built-in `sort` method, which handles comparisons for us: `list.sort()`.

Sort the list

Use Python’s built-in sorted function to sort the list of animal names alphabetically. Example: `sorted_animal_names = sorted(animal_names)`. This will automatically use uppercase characters in the comparison, sorting them alphabetically.

Output the sorted list

Print or return the sorted list of animal names to verify that the names have been sorted in alphabetical order. Example: `print(sorted_animal_names)` would display `['CAT', 'DOG', 'ELEPHANT', 'GIRAFFE', 'TIGER']`.

Key concepts

Comparison Functions

Comparison functions are essential tools in programming, especially when you need to determine the order of items or check whether items are equal. In C++ programming, comparison functions often guide sorting operations by comparing two elements and returning a value that signifies their order. The function typically returns:

• A negative value if the first element is less than the second.
• Zero if both elements are equal.
• A positive value if the first element is greater than the second.

In the context of alphabetizing, comparison functions can compare strings wherein each character is evaluated according to its corresponding position in the Unicode table.
When alphabetizing animal names, it's crucial to convert them to uppercase to ensure consistency. This is because the Unicode values for uppercase and lowercase letters differ, which can result in incorrect alphabetical orders if case-sensitivity isn't addressed. Therefore, by uniformly using uppercase, you avoid discrepancies and get a correct alphabetical sequence.

Alphabetization

Alphabetization is the process of arranging words or sequences in order based on the letters of the English alphabet. It’s a fundamental operation in many programming tasks and aids in organization and search optimization. In C++, alphabetizing strings often involves leveraging comparison functions and ensuring uniform character case.

• Start by ensuring that all strings are in uppercase or lowercase, avoiding mixed cases.
• Consider using standard library functions that implement efficient sorting algorithms.

When dealing with words like animal names, converting to uppercase simplifies the comparison approach. The C++ functions return values based on the alphabetical sequence defined by the character set, which means comparisons are based on the ASCII values of the characters. By doing this, you create a predictable and accurate ordering system. Using the C++ standard library's functionalities such as `sort`, alphabetization becomes straightforward. This method automates the process and achieves accurate results with minimal effort.

Sorting Algorithms

Sorting algorithms are techniques used to rearrange a sequence of elements into a particular order, most commonly ascending or descending. In C++, several sorting algorithms can help achieve alphabetization of strings.

• Bubble Sort: A simple but inefficient algorithm that repeatedly steps through the list, compares adjacent elements, and swaps them if they are in the wrong order.
• Selection Sort: Builds the sorted array one item at a time, by repeatedly finding the minimum (or maximum) element from the unsorted part and moving it to the sorted part.
• Quick Sort: Combines the divide-and-conquer paradigm to sort items quickly and efficiently.

The most common approach is to use the built-in sorting algorithm provided by the C++ Standard Library. Functions like `std::sort` implement highly efficient algorithms such as introsort, which is a hybrid sorting algorithm using quicksort, heapsort, and insertion sort. These tools optimize sorting operations and are suitable for alphabetizing large datasets. By using these functions, you can sort lists with fewer lines of code, consequently improving readability and maintainability of the program.