AP Computer Science A Flashcards: Implementing String Algorithms
Written by AP Content Team, Verified for 2026 AP Exams, Last updated: May 2026
Review key ideas with interactive flashcards. This set includes 10 cards to help you master important concepts.
What are three common tasks performed by standard string algorithms?
Standard string algorithms are used to find substrings with a particular property, count substrings meeting criteria, and create a new string with reversed characters.
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What are three common tasks performed by standard string algorithms?
Standard string algorithms are used to find substrings with a particular property, count substrings meeting criteria, and create a new string with reversed characters.
Which type of standard string algorithm would you use to verify if a username string contains any invalid characters?
You would use an algorithm designed to find if one or more substrings have a particular property (in this case, the property of being an invalid character).
What are the two main skills required when implementing string algorithms?
The two main skills are to develop code for standard and original algorithms involving strings and to be able to determine the result of these algorithms.
What does it mean to 'determine the result' of a string algorithm?
It means to trace the algorithm's logic with a given input string to predict its final output, such as a new string, a number, or a boolean value.
What is the goal of an algorithm that creates a new string with characters reversed?
The goal is to produce a new string that contains all the characters of the original string but in the opposite order.
What is the key difference between an algorithm that finds a property and one that counts occurrences of that property?
An algorithm to find a property can stop once the first instance is found, while an algorithm to count occurrences must process the entire string.
A program needs to count how many times the letter 'a' appears in a paragraph. Which category of string algorithm does this task belong to?
This task belongs to the category of algorithms that determine the number of substrings that meet specific criteria.
Why is it necessary to develop both 'standard' and 'original' algorithms?
Standard algorithms solve common, well-defined problems, while original algorithms are needed to solve new or unique problems not covered by standard approaches.
If an algorithm processes the string 'drawer' and returns 'reward', what standard algorithm was most likely used?
The algorithm used was one that creates a new string with the characters of the original string reversed.
Define a 'substring' in the context of string algorithms.
A substring is a contiguous sequence of characters within a larger string; it can be as short as a single character.