Review of fundamental C++ concepts and syntax

C++ is a powerful programming language that is extensively used in competitive programming due to its efficiency, flexibility, and wide range of features. In this article, we will review some fundamental concepts and syntax of C++ that are important for competitive programming.

Basic syntax and structure

C++ code is organized into functions, which are blocks of code that perform a specific task. The main function is the starting point of every C++ program. It is defined as follows:

int main() {
    // Code goes here
    return 0;
}

C++ statements must end with a semicolon (;), and blocks of code are enclosed in curly braces ({ }). The return statement is used to exit a function, and the value 0 indicates a successful program termination.

Variables and data types

Variables are used to store values in C++. Before using a variable, it must be declared by specifying its data type. C++ supports several built-in data types, such as int (for integers), float (for floating-point numbers), char (for characters), and bool (for boolean values).

Here's an example of declaring and initializing variables:

int age = 25;
float pi = 3.14;
char grade = 'A';
bool is_valid = true;

C++ also supports arrays, which are collections of elements of the same data type. Arrays are declared using square brackets ([]), and individual elements can be accessed using the index.

Control flow statements

Control flow statements are used to control the execution order of a program. C++ provides several control flow statements, including:

• If-else statements: Used to perform different actions based on a condition. The syntax is as follows:

if (condition) {
    // Code to execute if the condition is true
} else {
    // Code to execute if the condition is false
}

• For loops: Used to repeat a block of code for a specific number of times. The syntax is as follows:

for (initialization; condition; update) {
    // Code to execute in each iteration
}

• While loops: Used to repeat a block of code as long as a condition is true. The syntax is as follows:

while (condition) {
    // Code to execute in each iteration
}

• Switch statements: Used to select one of many code blocks to be executed. The syntax is as follows:

switch (variable) {
    case value1:
        // Code to execute if variable equals value1
        break;
    case value2:
        // Code to execute if variable equals value2
        break;
    // ...
    default:
        // Code to execute if variable does not match any of the cases
}

Functions

Functions in C++ are blocks of code that can be called from other parts of the program. They are defined with a return type, name, and optional parameters.

Here's an example of a function that calculates the sum of two numbers:

int sum(int a, int b) {
    return a + b;
}

To call this function and store the result in a variable, we can do:

int result = sum(5, 3);

Conclusion

This article provided a brief review of fundamental C++ concepts and syntax that are commonly used in competitive programming. By understanding these basics, you'll have a solid foundation to build upon and tackle more advanced programming problems. Happy coding!