How to use a Stack in C++

A stack is a linear data structure that follows the Last-In-First-Out (LIFO) principle, where the last element added to the stack is the first one to be removed. It consists of two main operations: push, which adds an element to the top of the stack, and pop, which removes the top element from the stack. Additionally, there is a peek operation that allows you to view the top element without removing it. Stacks are commonly used in programming languages for function calls, as well as in algorithms such as depth-first search and backtracking. Keep reading below to learn how to use a Stack in C++.

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How to use a Stack in C++ with example code

A Stack is a data structure that follows the Last-In-First-Out (LIFO) principle. It is used to store and retrieve data in a specific order. In C++, a Stack can be implemented using an array or a linked list.

To use a Stack in C++, you need to include the header file. The Stack class is defined in this header file. Here is an example code to create a Stack of integers using an array:

#include #include


using namespace std;
int main() {

    stack s;
    s.push(10);

    s.push(20);

    s.push(30);

cout << "Stack size: " << s.size() << endl; cout << "Top element: " << s.top() << endl; s.pop(); cout << "Stack size after pop: " << s.size() << endl; cout << "Top element after pop: " << s.top() << endl; return 0; }

In this example, we first create a Stack of integers using the stack s; statement. We then push three integers (10, 20, and 30) onto the Stack using the s.push() method. We print the size of the Stack and the top element using the s.size() and s.top() methods, respectively.

We then pop the top element from the Stack using the s.pop() method. We print the size of the Stack and the top element again to see the changes.

The output of this program will be:

Stack size: 3
Top element: 30
Stack size after pop: 2
Top element after pop: 20

As you can see, the Stack follows the LIFO principle. The last element that was pushed onto the Stack (30) is the first one to be popped off the Stack.

What is a Stack in C++?

In conclusion, a stack in C++ is a data structure that follows the Last-In-First-Out (LIFO) principle. It is a container that allows elements to be inserted and removed only from one end, known as the top of the stack. The stack is a useful tool for solving problems that require a temporary storage of data, such as reversing a string or evaluating expressions. In C++, the stack is implemented as a container adapter, which means it is built on top of other container classes, such as vectors or lists. With its simple and efficient operations, the stack is a fundamental concept in computer science and programming, and it is essential for any programmer to understand its basic principles and usage.