Ascending Repeating Shrinking Pattern in C

Beginner
⏱️ 5 min read
📚 Updated: Aug 2025
🎯 2 Code Examples
Nested Loops
Ascending repeating shrinking pattern output (11111, 2222, 333, 44, 5) in C programming

What You’ll Learn

How to print an ascending repeating number shrinking pattern in C. The digit increases each row, but the number of repeats decreases each row.

This is a great exercise to learn how expressions like rows - i + 1 can control the inner-loop length.

⭐ Pattern Output

For rows = 5, the pattern looks like this:

Output
11111
2222
333
44
5
1

Complete C Program

The inner loop runs rows - i + 1 times, which shrinks the row as i increases.

c
#include <stdio.h>

int main() {
    int rows = 5;
    int i, j;

    for (i = 1; i <= rows; ++i) {
        for (j = 1; j <= rows - i + 1; ++j) {
            printf("%d", i);
        }
        printf("\n");
    }

    return 0;
}

🧠 How It Works

1

Set rows

rows is the maximum digit and also controls triangle height.

Setup
2

Outer loop (digit)

i increases from 1 to rows, choosing the digit to repeat on each row.

Digit increases
3

Inner loop (repeat count)

rows - i + 1 gives the repetition count. It decreases by one each row, shrinking the line length.

Rows shrink
4

New line

printf("\n") completes the row.

Line break
=

Shrinking repetition

Total prints are 1+2+…+n = n(n+1)/2, so runtime is O(n²).

2

Variation — User Input Version

Accept the number of rows from the user using scanf():

c
#include <stdio.h>

int main() {
    int rows;
    int i, j;

    printf("Enter the number of rows: ");
    scanf("%d", &rows);

    for (i = 1; i <= rows; ++i) {
        for (j = 1; j <= rows - i + 1; ++j) {
            printf("%d", i);
        }
        printf("\n");
    }

    return 0;
}

💡 Tips for Enhancement

Try These

  • Make it grow by using j <= i instead of rows - i + 1
  • Add spaces with printf("%d ", i)
  • Try letters instead of digits for AAAA, BBB, CC...
  • Right-align by adding leading spaces before each row

Avoid

  • Hard-coding the row count
  • Forgetting the newline after each row
  • Using negative rows without validation

Key Takeaways

1

The printed digit is the row index i.

2

The repetition count is rows - i + 1, which decreases each row.

3

Total prints are n(n+1)/2, so runtime is O(n²).

4

This is the shrinking counterpart to repeating triangles like Program 9.

❓ Frequently Asked Questions

Because the inner loop runs only rows - i + 1 times, which decreases as i increases.
Use for (j = 1; j <= i; ++j) so each next row prints one more digit.
O(n²) because total prints are 1+2+…+n = n(n+1)/2.

Explore More Pattern Variations

Try combining repetition rules with alternating row logic for new zigzag patterns.

All Number Patterns →
Did you know?

The expression rows - i + 1 is a common trick for shrinking patterns. You’ll see it again in inverted triangles and right-aligned shapes.

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.

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