Reverse a Sentence using Stacks in c++

 

Reverse a Sentence using Stacks in C++

Stacks are a fundamental data structure that is commonly used in computer science and programming. They are a type of data structure that follows the Last In First Out (LIFO) principle, which means that the last element that is added to the stack is the first one to be removed. This principle makes stacks ideal for use in a variety of applications, including reversing a sentence.

Reversing a sentence can be a useful task in various situations, such as when analyzing text data or when creating a program that generates a sentence in reverse order. In this article, we will explore how to reverse a sentence using stacks in C++.

To begin, we need to first understand the basic concept of a stack. A stack is a collection of elements that are stored in a specific order. The elements in a stack are added and removed based on the LIFO principle. The element that is added last is the first one to be removed, and the element that is added first is the last one to be removed.

In C++, we can implement a stack using an array or a linked list. For this article, we will be using an array to implement the stack. The array will store the characters of the sentence, and we will use the push() and pop() functions to add and remove elements from the stack. The push() function adds an element to the top of the stack, and the pop() function removes the element from the top of the stack.

Here is an example of how to implement a stack in C++ using an array:

#include <iostream>
 
using namespace std; 
 const int MAX_SIZE = 100;
 class Stack {
 private:
 char arr[MAX_SIZE];
 int top;
 public:
 Stack() {
 top = -1; 
 } 
 void push(char ch) {
 if (top == MAX_SIZE - 1)
 {
 cout << "Stack Overflow" << endl;
 } 
else {
 top++; 
 arr[top] = ch;
 }
    } 
 char pop() {
 if (top == -1) 
{ 
 cout << "Stack Underflow" << endl;
 }
 else { 
 char ch = arr[top];
 top--;
 return ch; 
 } 
 }
 };

Once we have the stack implementation in place, we can move on to reversing the sentence. To reverse a sentence, we need to first read the sentence and then push each character of the sentence onto the stack. Once all the characters are in the stack, we can use the pop() function to remove the characters from the stack, and print them in reverse order.

Here is an example of how to reverse a sentence using stacks in C++:

#include <iostream>
 
using namespace std;
 int main() {
 string sentence; 
 cout << "Enter a sentence: ";
 getline(cin, sentence); 
 Stack stack;
 for (int i = 0;
 i < sentence.length();
 i++) { 
 stack.push(sentence[i]);
 }
 cout << "Reversed sentence: ";
 while (stack.top != -1) 
{ 
 cout << stack.pop();
 }
 cout << endl;
 return 0;
 }

In this example, the program first prompts

Algorithm for Reversing a Sentence using Stacks in C++:

1. Create an instance of the stack class.
2. Input a sentence from the user using the getline() function.
3. Iterate through the sentence, and push each character onto the stack using the push() function.
4. Create a while loop that continues until the top of the stack is -1.
5. Inside the while loop, use the pop() function to remove the top character from the stack and print it.
6. Once the while loop is finished, the sentence will be reversed and printed out.

create an instance of the stack class
 
input a sentence from the user using the getline() function 
for i = 0 to sentence.length()
 stack.push(sentence[i]) 
create a while loop 
 while (stack.top != -1) 
 print stack.pop()

This algorithm is simple and efficient, as it uses the LIFO principle of the stack to reverse the sentence in a linear time complexity. The algorithm also utilizes the push() and pop() functions of the stack to add and remove characters, making it easy to understand and implement.