Introduction to Stacks

In the field of computer science and programming, a stack is an abstract data type that represents a collection of elements. It follows the Last-In-First-Out (LIFO) principle, meaning that the last element added to the stack is the first one to be removed.

1#include <iostream>
2using namespace std;
3
4int main() {
5  // Creating a stack using an array
6  int stack[5];
7  int top = -1;
8
9  // Push operation
10  top++;
11  stack[top] = 1;
12  top++;
13  stack[top] = 2;
14  top++;
15  stack[top] = 3;
16
17  // Pop operation
18  top--;
19
20  // Peek operation
21  cout << "Top element: " << stack[top] << endl;
22
23  return 0;
24}

Let's break down the code snippet above:

• We first declare an array stack which will be used to store the elements of the stack.

• We also declare a variable top to keep track of the index of the top element in the stack.

• In the push operation, we increment top by 1 and assign the element to be added to the stack at stack[top].

• In the pop operation, we decrement top by 1 to remove the top element from the stack.

• In the peek operation, we simply print the top element of the stack.

Using this code snippet as an example, you can see the basic implementation of a stack using an array in C++. The principles and concepts discussed here can be applied to other programming languages as well.

Next, we will dive deeper into implementing the stack data structure and exploring its associated methods.

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#include <iostream>

using namespace std;

​

int main() {

  // Creating a stack using an array

  int stack[5];

  int top = -1;

​

  // Push operation

  top++;

  stack[top] = 1;

  top++;

  stack[top] = 2;

  top++;

  stack[top] = 3;

​

  // Pop operation

  top--;

​

  // Peek operation

  cout << "Top element: " << stack[top] << endl;

​

  return 0;

}