📅 Date: Feb 4, 2026
🔥 Topic: Pyramids, Diamonds & The Butterfly

📐 Handling Spaces

Advanced patterns require us to print Spaces before printing Stars. This usually means we need THREE loops (Outer, Inner-Space, Inner-Star).

1️⃣ Star Pyramid (The Classic)

Calculated logic: Spaces = n - i, Stars = 2*i - 1.

   *
  ***
 *****
*******
    
for(int i=1; i<=n; i++) {
    // Spaces
    for(int j=1; j<=n-i; j++) {
        cout << " ";
    }
    // Stars
    for(int j=1; j<=2*i-1; j++) {
        cout << "*";
    }
    cout << endl;
}

2️⃣ Diamond Pattern

A full diamond is just a Pyramid + Inverted Pyramid.

// Upper Half
for(int i=1; i<=n; i++) {
    for(int j=1; j<=n-i; j++) cout << " ";
    for(int j=1; j<=2*i-1; j++) cout << "*";
    cout << endl;
}
// Lower Half
for(int i=n; i>=1; i--) {
    for(int j=1; j<=n-i; j++) cout << " ";
    for(int j=1; j<=2*i-1; j++) cout << "*";
    cout << endl;
}

3️⃣ The Butterfly Pattern 🦋 (Interview Favorite)

This looks complex but it's symmetrical.

* *
** **
*** ***
** **
* *
    
// Upper Wing
for(int i=1; i<=n; i++) {
    // Stars
    for(int j=1; j<=i; j++) cout << "*";
    
    // Spaces (2 * (n-i))
    int spaces = 2 * (n-i);
    for(int j=1; j<=spaces; j++) cout << " ";
    
    // Stars
    for(int j=1; j<=i; j++) cout << "*";
    cout << endl;
}

// Lower Wing (Reverse Logic)
for(int i=n; i>=1; i--) {
    for(int j=1; j<=i; j++) cout << "*";
    int spaces = 2 * (n-i);
    for(int j=1; j<=spaces; j++) cout << " ";
    for(int j=1; j<=i; j++) cout << "*";
    cout << endl;
}

⏭️ Next Up: OOPs Concepts

I have mastered Loops, Arrays, Strings, and Logic.
Now it's time to learn the pillar of modern software development: Object Oriented Programming (OOPs).
Classes, Objects, Inheritance... coming soon!