Program to print number pattern in C

Numerical patterns in C programming involve printing sequences of numbers arranged in specific shapes or structures. These patterns follow mathematical rules and are excellent for practicing nested loops and logical thinking.

Syntax

for(i = start; condition; increment/decrement) {
    for(j = start; condition; increment/decrement) {
        printf("format", value);
    }
    printf("<br>");
}

Example 1: Triangular Number Pattern

This pattern displays numbers in a triangular format where each row contains specific values based on a mathematical formula −

#include <stdio.h>

int main() {
    int i, j, k;
    
    printf("Triangular Number Pattern:<br><br>");
    
    for(i = 1; i <= 5; i++) {
        k = i;
        for(j = 1; j <= i; j++) {
            printf("%d ", k);
            k += 5 - j;
        }
        printf("<br>");
    }
    
    return 0;
}

Triangular Number Pattern:

1 
2 6 
3 7 10 
4 8 11 13 
5 9 12 14 15 

Example 2: Diamond Number Pattern

This creates a diamond shape with numbers, expanding from 1 to the maximum row and then contracting back −

#include <stdio.h>

int main() {
    int i, j, k;
    
    printf("Diamond Number Pattern:<br><br>");
    
    /* Upper half of diamond */
    for(i = 1; i <= 5; i++) {
        /* Print leading spaces */
        for(j = i; j < 5; j++) {
            printf("  ");
        }
        /* Print numbers */
        for(k = 1; k < (i * 2); k++) {
            printf("%d ", k);
        }
        printf("<br>");
    }
    
    /* Lower half of diamond */
    for(i = 4; i >= 1; i--) {
        /* Print leading spaces */
        for(j = 5; j > i; j--) {
            printf("  ");
        }
        /* Print numbers */
        for(k = 1; k < (i * 2); k++) {
            printf("%d ", k);
        }
        printf("<br>");
    }
    
    return 0;
}

Diamond Number Pattern:

        1 
      1 2 3 
    1 2 3 4 5 
  1 2 3 4 5 6 7 
1 2 3 4 5 6 7 8 9 
  1 2 3 4 5 6 7 
    1 2 3 4 5 
      1 2 3 
        1 

How It Works

• Pattern 1: Uses variable k initialized to row number i, then increments by (5-j) for each position.
• Pattern 2: Creates diamond by printing spaces followed by consecutive numbers, with rows expanding then contracting.
• Both patterns use nested loops where outer loop controls rows and inner loops handle spacing and number printing.

Key Points

• Nested loops are essential for creating 2D patterns in C.
• Mathematical formulas determine the relationship between row position and displayed values.
• Proper spacing using loops creates visual alignment in patterns.

Conclusion

Number patterns in C demonstrate the power of nested loops and mathematical logic. These examples show how to create both simple triangular and complex diamond patterns using systematic approaches.