C++ Program to Print Inverted Pyramid

Creating an inverted pyramid in C++ is a straightforward task that involves careful manipulation of loops to print elements in a specific format. This task demonstrates the use of nested loops and control structures to create a pattern that resembles an upside-down pyramid, typically constructed using asterisks (*).

Understanding the Structure

An inverted pyramid consists of rows of elements that start with a relatively large number on the top row and decrease in each subsequent row. For a traditional pyramid pattern printed with stars, an inverted version would start with the widest row of stars at the top and reduce the number of stars by a fixed amount in each subsequent row until it reaches the smallest row at the bottom.

Program Outline

The C++ program will perform the following tasks:

1. Prompt the user to input the number of rows for the inverted pyramid.
2. Use a loop to iterate from the number of rows down to one.
3. In each iteration, print the required number of stars and spaces to create the inverted pyramid appearance.

Detailed C++ Program

#include <iostream>

using namespace std;

int main() {

    int rows;

    cout << “Enter the number of rows for the inverted pyramid: “;

    cin >> rows;

    // Outer loop decrements to reduce the number of stars in each row

    for (int i = rows; i > 0; i–) {

        // Print leading spaces to center the stars

        for (int space = 0; space < rows – i; space++) {

            cout << ” “;

        }

        // Print stars: number of stars decreases as the loop decrements

        for (int star = 1; star <= 2 * i – 1; star++) {

            cout << “*”;

        }

        cout << endl;  // Move to the next line after each row is printed

    }

    return 0;

}

Breakdown of the Program

1. User Input for Rows:

The program prompts the user to specify the number of rows, which will determine the base width of the pyramid.

2. Outer Loop:

This loop starts from the number of rows and decrements down to 1. Each loop iteration corresponds to a row in the inverted pyramid, starting from the widest part.

3. Inner Loop for Spaces:

Before printing stars, this loop prints spaces to ensure the stars are centered appropriately. The number of spaces is fewer for upper rows and increases as the pyramid narrows (as we move upwards in terms of traditional pyramid structure).

4. Inner Loop for Stars:

This loop is responsible for printing the stars. The number of stars starts from the maximum (2 * rows – 1 for the first row) and decreases as we move to subsequent rows. The formula 2 * i – 1 ensures the correct number of stars is printed, which decrements symmetrically.

5. Line Break After Each Row:

A newline (endl) is printed at the end of each row to start a new line for the subsequent row.