Print a Butterfly Alphabet Pattern in C

To print a butterfly alphabet pattern in C, we use nested loops to create the upper and lower halves of the pattern. The pattern consists of letters arranged symmetrically to form a butterfly shape, where the left and right wings mirror each other.

Example 1: Basic Butterfly Alphabet Pattern Using Characters

In this example, we will create a butterfly pattern using letters starting from ‘A’. The pattern will be symmetric, where the left and right sides mirror each other.

main.c

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#include <stdio.h>

int main() {
    int n = 5;
    
    // Upper half of the butterfly
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= i; j++) {
            printf("%c ", 'A' + j - 1);
        }
        for (int j = 1; j <= 2 * (n - i); j++) {
            printf("  ");
        }
        for (int j = i; j >= 1; j--) {
            printf("%c ", 'A' + j - 1);
        }
        printf("\n");
    }

    // Lower half of the butterfly
    for (int i = n-1; i >= 1; i--) {
        for (int j = 1; j <= i; j++) {
            printf("%c ", 'A' + j - 1);
        }
        for (int j = 1; j <= 2 * (n - i); j++) {
            printf("  ");
        }
        for (int j = i; j >= 1; j--) {
            printf("%c ", 'A' + j - 1);
        }
        printf("\n");
    }

    return 0;
}

Explanation:

  1. We declare an integer n = 5 to define the pattern size.
  2. The first nested loop prints the upper half of the butterfly:
    • The first for loop prints letters from ‘A’ up to the current row number. Refer: C For Loop.
    • The second for loop prints spaces to create the gap in the middle.
    • The third for loop prints letters in reverse order to complete the mirror effect.
  3. The second nested loop prints the lower half, using the same logic but in reverse order.

Output:

A                 A 
A B             B A 
A B C         C B A 
A B C D     D C B A 
A B C D E E D C B A 
A B C D     D C B A 
A B C         C B A 
A B             B A 
A                 A

Example 2: Butterfly Alphabet Pattern with Repeating Letters

In this example, we modify the butterfly pattern so that each row contains repeating letters instead of sequential characters.

main.c

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#include <stdio.h>

int main() {
    int n = 5;

    // Upper half
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= i; j++) {
            printf("%c ", 'A' + i - 1);
        }
        for (int j = 1; j <= 2 * (n - i); j++) {
            printf("  ");
        }
        for (int j = 1; j <= i; j++) {
            printf("%c ", 'A' + i - 1);
        }
        printf("\n");
    }

    // Lower half
    for (int i = n-1; i >= 1; i--) {
        for (int j = 1; j <= i; j++) {
            printf("%c ", 'A' + i - 1);
        }
        for (int j = 1; j <= 2 * (n - i); j++) {
            printf("  ");
        }
        for (int j = 1; j <= i; j++) {
            printf("%c ", 'A' + i - 1);
        }
        printf("\n");
    }

    return 0;
}

Explanation:

  1. We set n = 5 to determine the number of rows.
  2. The first loop prints the upper half:
    • Each row prints the same letter corresponding to its row number.
    • Spaces are added in the middle to maintain the butterfly shape.
  3. The second loop prints the lower half in reverse order.

Output:

A                 A 
B B             B B 
C C C         C C C 
D D D D     D D D D 
E E E E E E E E E E 
D D D D     D D D D 
C C C         C C C 
B B             B B 
A                 A

Conclusion

In this tutorial, we explored how to print butterfly alphabet patterns in C. We covered:

  1. Basic Butterfly Alphabet Pattern: A symmetrical pattern using sequential characters.
  2. Repeating Letters Butterfly Pattern: Each row consists of the same letter for a different effect.