Symmetric Alphabet, Star Center

Beginner
⏱️ 7 min read
📚 Updated: Aug 2025
🎯 2 Code Examples
Nested Loops
Symmetric alphabet pattern with stars between mirrored halves in C++

What You’ll Learn

Build rows that read the same forwards and backwards on the letters, with * filling the gap in the middle as the row shortens.

The classic reference form uses ASCII values (65.. 69) and prints \"**\" pairs in the middle to keep symmetry.

⭐ Pattern Output

For n = 5:

Output
ABCDEEDCBA
ABCD**DCBA
ABC****CBA
AB******BA
A********A
1

Complete C++ Program (Reference Logic)

Three zones per row: left letters, star gap, right letters. The star loop prints \"**\" (two stars) per iteration, so the center width grows by 2 each row.

C++
#include <iostream>
using namespace std;

int main() {
    int i, j, k, m;
    for (i = 69; i >= 65; i--) {
        for (j = 65; j <= i; j++)
            cout << (char) j;
        for (k = i; k < 69; k++)
            cout << \"**\";
        for (m = i; m >= 65; m--)
            cout << (char) m;
        cout << \"\\n\";
    }
    return 0;
}

🧠 How It Works

1

Outer i = 'E' .. 'A'

The end letter shrinks each row: E, D, C, B, A.

Rows
2

Left half j = 'A' .. i

Print a prefix from A up to the current row end letter.

Up
3

Star gap \"**\"

The loop runs 69 - i times and prints two stars per step, so stars = 2*(69 - i).

Center
4

Right half m = i .. 'A'

Mirror the left side by printing descending letters.

Down
=

Characters per row

For n = 5, each row prints 10 characters total (letters + stars + letters).

2

Variation — User Input (General n)

Use top = base + rows - 1. The star count becomes 2*(top - i), so it grows by 2 each row as the letter range shrinks.

C++
#include <iostream>
using namespace std;

int main() {
    int rows;
    int i, j, k, m;
    const int base = 65;

    cout << \"Enter the number of rows: \";
    cin >> rows;

    int top = base + rows - 1;
    for (i = top; i >= base; i--) {
        for (j = base; j <= i; j++)
            cout << (char) j;

        for (k = i; k < top; k++)
            cout << \"**\";

        for (m = i; m >= base; m--)
            cout << (char) m;

        cout << \"\\n\";
    }

    return 0;
}

💡 Tips for Enhancement

Try These

  • Swap * for spaces or . for a softer look
  • Trace one row: track the last printed letter and the star count 2*(top - i)
  • Clamp rows so top stays within 'A'.. 'Z'

Avoid

  • Printing \"*\" once per iteration if you want the exact reference output (it uses \"**\")
  • Using 2 * i for stars instead of 2 * (top - i) (center width flips)

Key Takeaways

1

Three zones per row: ascending letters, stars, descending letters.

2

The middle grows by 2 stars each row: 2*(top - i).

3

For fixed n, each row prints 2n total characters in this pattern family.

4

Overall time O(n²) for n rows.

❓ Frequently Asked Questions

When i == top, the gap is 2*(top - i) = 0. The two halves meet directly: ABCDE + EDCBA.
It doubles the center width so the overall row stays symmetric in even steps: 0, 2, 4, 6, 8 stars for five rows.
The outer loop won’t run. In real programs, validate input so rows >= 1.
O(n²) for n rows.

Explore More C++ Alphabet Patterns!

Mixing letters and stars is the same idea as hollow or diamond star programs — split each row into zones.

All Alphabet Patterns →
Did you know?

For fixed n, each row prints exactly 2n characters total (letters + stars + letters). That makes it easy to center-align the pattern in monospaced output if you want to extend it.

About the author

Mari Selvan M P
Mari Selvan M P 🔗

Developer, cloud engineer, and technical writer

  • Experience 12 years building web and cloud systems
  • Focus Full Stack Development, AWS, and Developer Education

I write practical tutorials so students and working developers can learn by doing—from databases and APIs to deployment on AWS.

AWS Certified Developer – Associate (Credly)

12 people found this page helpful

C++ Alphabet Pattern 14 C++ Alphabet Pattern 16