Printing Pyramid Patterns

Given a positive integer n, print a pyramid pattern consisting of stars (*) such that the number of rows equals n. The pyramid should be center-aligned as shown in the example below.

Example:

Input: n = 5
Output:

Explanation: Here, the total number of rows is 5, which forms a pyramid structure.

Input: n = 3
Output:

Input: n = 7
Output:

Using Two Loops - O( n^2) Time and O(1) Space

The idea is to use two nested loops. The outer loop is used to track the rows, while the inner loops are used to print the required spaces and stars for each row.

Illustration:

• For every row i (from 1 to n), the pyramid must remain center aligned.
• First print spaces, then print stars (*).
• The number of leading spaces for row i is n - i, which decreases as the row increases.
• After spaces, print 2 × i − 1 stars.
• This pattern makes the pyramid grow symmetrically from the center.

//Driver Code Starts
#include <iostream>
using namespace std;

//Driver Code Ends

void printPyramid(int n) {
    
    // Outer loop for rows
    for (int i = 1; i <= n; i++) {
        
        // Print spaces 
        for (int j = 1; j <= n - i; j++)
            cout << " ";
        
        // Print stars
        for (int j = 1; j <= 2 * i - 1; j++)
            cout << "*";
        
        cout << endl;
    }
}

//Driver Code Starts

int main() {
    int n = 5;
    printPyramid(n);
    return 0;
}
//Driver Code Ends

//Driver Code Starts
class GfG {

//Driver Code Ends

    static void printPyramid(int n) {

        // Outer loop for rows
        for (int i = 1; i <= n; i++) {

            // Print spaces
            for (int j = 1; j <= n - i; j++)
                System.out.print(" ");

            // Print stars
            for (int j = 1; j <= 2 * i - 1; j++)
                System.out.print("*");

            System.out.println();
        }
    }

//Driver Code Starts

    public static void main(String[] args) {
        int n = 5;
        printPyramid(n);
    }
}
//Driver Code Ends

def print_pyramid(n):

    # Outer loop for rows
    for i in range(1, n + 1):

        # Print spaces
        print(" " * (n - i), end="")

        # Print stars
        print("*" * (2 * i - 1))


#Driver Code Starts
if __name__=="__main__":
    n = 5
    print_pyramid(n)
#Driver Code Ends

//Driver Code Starts
using System;

class GfG
{
//Driver Code Ends

    static void PrintPyramid(int n)
    {
        for (int i = 1; i <= n; i++)
        {
            string row = "";

            // Spaces
            for (int j = 1; j <= n - i; j++)
                row += " ";

            // Stars
            for (int j = 1; j <= 2 * i - 1; j++)
                row += "*";

            Console.WriteLine(row);
        }
    }

//Driver Code Starts

    static void Main()
    {
        int n=5;
        PrintPyramid(n);
    }
}
//Driver Code Ends

function printPyramid(n) {

    for (let i = 1; i <= n; i++) {

        let row = "";

        // Spaces
        for (let j = 1; j <= n - i; j++)
            row += " ";

        // Stars
        for (let j = 1; j <= 2 * i - 1; j++)
            row += "*";

        console.log(row);
    }
}


//Driver Code Starts
// Driver code
let n=5;
printPyramid(n);
//Driver Code Ends