Developing Algorithms Using Strings

Introduction to Strings

Strings are sequences of characters, and are a key data type in most programming languages.
Each individual character in a string can be accessed using its index. Indices start at 0 and increment by 1 for each subsequent character.
Strings are immutable, meaning you can’t change their characters without creating a new string.

Concatenation is an operation that combines two strings into one.
The length operation returns the number of characters in a string.
Substring operation selects a range of characters from a string based on their indices.
Checking for equality of two strings compares them character by character, and considers case.

A loop can go through each character in a string one by one, performing some operation at each step.
A for loop is often used for iterating over strings as you typically know how many cycles you’re going to need (as many as there are characters in the string).
Within the loop, you can access each character using its index.
Nested loops can be used to compare characters at different positions in two or more strings.

Algorithms often need to find patterns in strings, count occurrences of characters, or transform strings in some way.
String manipulation is a key part of many algorithms. It requires understanding of how strings are structured and how to access and compare their characters.
Iteration is typically used to work through the string character by character.
Examples of string-related algorithm problems: finding the longest repeating sequence of characters, checking whether a string is a palindrome, and finding the most common character.

Some algorithms require more complex operations like reversing a string, splitting a string into substrings, or replacing parts of a string with other strings.
These operations typically involve creating new strings as the original strings can’t be changed.
Advanced string manipulation often involves multiple iterations through the string as well as conditional logic.