Pattern Programs in C

Printing patterns using C programs has always been an interesting problem domain. We can print different patterns like star patterns, pyramid patterns, Floyd’s triangle, Pascal’s triangle, etc. in C language. These problems generally require the knowledge of loops and if-else statements.

Pattern Programs in C

In this article, we will discuss the following example programs for printing patterns in the C programming language.

1. Right Half Pyramid Pattern
2. Left Half Pyramid Pattern
3. Full Pyramid Pattern
4. Inverted Right Half Pyramid Pattern
5. Inverted Left Half Pyramid Pattern
6. Inverted Full Pyramid Pattern
7. Rhombus Pattern
8. Diamond Pattern
9. Hourglass Pattern
10. Hollow Square Pattern
11. Hollow Full Pyramid Pattern
12. Hollow Inverted Full Pyramid Pattern
13. Hollow Diamond Pattern
14. Hollow Hourglass Pattern
15. Floyd’s Triangle Pattern
16. Pascal’s Triangle Pattern

Programs to Print Patterns in C

1. Right Half Pyramid Pattern in C

The right-half pyramid is nothing but a right-angle triangle whose hypotenuse is in the right direction. We can print the right half pyramid pattern using numbers, alphabets, or any other character like a star (*).

Example:

C

// C program to print right half pyramid pattern of star
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop for printing rows
    for (int i = 0; i < rows; i++) {

        // second loop for printing character in each rows
        for (int j = 0; j <= i; j++) {
            printf("* ");
        }
        printf("\n");
    }
    return 0;
}

C

// C program to print right half pyramid pattern of number
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop for printing rows
    for (int i = 0; i < rows; i++) {

        // second loop for printing number in each rows
        for (int j = 0; j <= i; j++) {
            printf("%d ", j + 1);
        }
        printf("\n");
    }
    return 0;
}

C

// C program to print right half pyramid pattern of
// alphabets
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop for printing rows
    for (int i = 0; i < rows; i++) {

        // second loop for printing alphabets in each rows
        for (int j = 0; j <= i; j++) {
            printf("%c ", 'A' + j);
        }
        printf("\n");
    }
    return 0;
}

Output

*           |   1           |   A
* *         |   1 2         |   A B
* * *       |   1 2 3       |   A B C
* * * *     |   1 2 3 4     |   A B C D
* * * * *   |   1 2 3 4 5   |   A B C D E

Time Complexity: O(rows*rows) as nested for loop is being run.
Auxiliary Space: O(1) as no extra space has been used.

2. Left Half Pyramid Pattern in C

The Left Half Pyramid looks like a right-angled triangle with its hypotenuse facing the left. We can also print this pattern using a character, alphabets, or numbers.

Example:

C

// c program to print left half pyramid pattern of star
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop is for printing the rows
    for (int i = 0; i < rows; i++) {

        // loop for printing leading whitespaces
        for (int j = 0; j < 2 * (rows - i) - 1; j++) {
            printf(" ");
        }

        // loop for printing * character
        for (int k = 0; k <= i; k++) {
            printf("* ");
        }
        printf("\n");
    }
    return 0;
}

C

// c program to print left half pyramid pattern of numbers
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop is for printing the rows
    for (int i = 0; i < rows; i++) {

        // loop for printing leading whitespaces
        for (int j = 0; j < 2 * (rows - i) - 2; j++) {
            printf(" ");
        }

        // loop for printing continious numbers
        for (int k = 0; k <= i; k++) {
            printf("%d ", k + 1);
        }
        printf("\n");
    }
    return 0;
}

C

// c program to print left half pyramid pattern of alphabets
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop is for printing the rows
    for (int i = 0; i < rows; i++) {

        // loop for printing leading whitespaces
        for (int j = 0; j < 2 * (rows - i) - 1; j++) {
            printf(" ");
        }

        // loop for printing alphabets
        for (int k = 0; k <= i; k++) {
            printf("%c ", 'A' + k);
        }
        printf("\n");
    }
    return 0;
}

Output

        *    |            1    |            A
      * *    |          1 2    |          A B
    * * *    |        1 2 3    |        A B C
  * * * *    |      1 2 3 4    |      A B C D
* * * * *    |    1 2 3 4 5    |    A B C D E

Time Complexity: O(rows*rows) as nested for loop is being run.
Auxiliary Space: O(1) as no extra space has been used.

3. Full Pyramid Pattern in C

The Full Pyramid pattern looks similar to the Equilateral triangle. We can see this as the combination of the Left Half and Right Half pyramids patterns. The following example demonstrates how to print this pattern using alphabets, numbers, or a star (*).

Example:

C

// C program to print the full pyramid pattern of stars
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop to print all rows
    for (int i = 0; i < rows; i++) {

        // inner loop 1 to print white spaces
        for (int j = 0; j < 2 * (rows - i) - 1; j++) {
            printf(" ");
        }

        // inner loop 2 to print star * character
        for (int k = 0; k < 2 * i + 1; k++) {
            printf("* ");
        }
        printf("\n");
    }
    return 0;
}

C

// C program to print the full pyramid pattern of alphabets
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop to print all rows
    for (int i = 0; i < rows; i++) {

        // inner loop 1 to print white spaces
        for (int j = 0; j < 2 * (rows - i) - 1; j++) {
            printf(" ");
        }

        // inner loop 2 to print alphabets
        for (int k = 0; k < 2 * i + 1; k++) {
            printf("%c ", 'A' + k);
        }
        printf("\n");
    }
    return 0;
}

C

// C program to print the full pyramid pattern of numbers
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop to print all rows
    for (int i = 0; i < rows; i++) {

        // inner loop 1 to print white spaces
        for (int j = 0; j < 2 * (rows - i) - 1; j++) {
            printf(" ");
        }

        // inner loop 2 to print star numbers
        for (int k = 0; k < 2 * i + 1; k++) {
            printf("%d ", k + 1);
        }
        printf("\n");
    }
    return 0;
}

Output

         *           |           1           |           A
       * * *         |         1 2 3         |         A B C
     * * * * *       |       1 2 3 4 5       |       A B C D E
   * * * * * * *     |     1 2 3 4 5 6 7     |     A B C D E F G
 * * * * * * * * *   |   1 2 3 4 5 6 7 8 9   |   A B C D E F G H I

Time Complexity: O(rows*rows) as nested for loop is being run.
Auxiliary Space: O(1) as no extra space has been used.

4. Inverted Right Half Pyramid Pattern in C

This pattern is the 180° flipped version of the Right Half Pyramid Pattern we discussed earlier.

Example:

C

// C program to print the inverted right half pyramid of
// stars
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop to print all rows
    for (int i = 0; i < rows; i++) {

        // first inner loop to print the * in each row
        for (int j = 0; j < rows - i; j++) {
            printf("* ");
        }
        printf("\n");
    }
}

C

// C program to print the inverted right half pyramid of
// numbers
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop to print all rows
    for (int i = 0; i < rows; i++) {

        // first inner loop to print the numbers in each row
        for (int j = 0; j < rows - i; j++) {
            printf("%d ", j + 1);
        }
        printf("\n");
    }
}

C

// C program to print the inverted right half pyramid of
// alphabets
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop to print all rows
    for (int i = 0; i < rows; i++) {

        // first inner loop to print the alphabets in each
        // row
        for (int j = 0; j < rows - i; j++) {
            printf("%c ", 'A' + j);
        }
        printf("\n");
    }
}

Output

* * * * *   |   1 2 3 4 5   |   A B C D E 
* * * *     |   1 2 3 4     |   A B C D
* * *       |   1 2 3       |   A B C
* *         |   1 2         |   A B
*           |   1           |   A

Time Complexity: O(rows*rows) as nested for loop is being run.
Auxiliary Space: O(1) as no extra space has been used.

5. Inverted Left Half Pyramid Pattern in C

This pattern is the 180° flipped version of the left half pyramid pattern we discussed earlier.

Example:

C

// C program to print the inverted left half pyramid pattern
// of stars
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop for printing all rows
    for (int i = 0; i < rows; i++) {

        // first inner loop for printing white spaces
        for (int j = 0; j < 2 * i; j++) {
            printf(" ");
        }

        // second inner loop for printing star *
        for (int k = 0; k < rows - i; k++) {
            printf("* ");
        }
        printf("\n");
    }

    return 0;
}

C

// C program to print the inverted left half pyramid pattern
// of numbers
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop for printing all rows
    for (int i = 0; i < rows; i++) {

        // first inner loop for printing white spaces
        for (int j = 0; j < 2 * i; j++) {
            printf(" ");
        }

        // second inner loop for printing numbers
        for (int k = 0; k < rows - i; k++) {
            printf("%d ", k + 1);
        }
        printf("\n");
    }

    return 0;
}

C

// C program to print the inverted left half pyramid pattern
// of alphabets
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop for printing all rows
    for (int i = 0; i < rows; i++) {

        // first inner loop for printing white spaces
        for (int j = 0; j < 2 * i; j++) {
            printf(" ");
        }

        // second inner loop for printing alphabets
        for (int k = 0; k < rows - i; k++) {
            printf("%c ", 'A' + k);
        }
        printf("\n");
    }

    return 0;
}

Output

* * * * *    |    1 2 3 4 5    |    A B C D E
  * * * *    |      1 2 3 4    |      A B C D
    * * *    |        1 2 3    |        A B C
      * *    |          1 2    |          A B
        *    |            1    |            A

Time Complexity: O(rows*rows) as nested for loop is being run.
Auxiliary Space: O(1) as no extra space has been used.

6. Inverted Full Pyramid Pattern in C

It is a 180° flipped version of the Full Pyramid Pattern we discussed earlier. We can see this as the combination of the Inverted Left Half and Inverted Right Half Pyramid Pattern we discussed earlier.

Example:

C

// C program to print the inverted full pyramid pattern of
// stars
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop for printing all rows
    for (int i = 0; i < rows; i++) {

        // first inner loop for printing leading white
        // spaces
        for (int j = 0; j < 2 * i; j++) {
            printf(" ");
        }

        // second inner loop for printing stars *
        for (int k = 0; k < 2 * (rows - i) - 1; k++) {
            printf("* ");
        }
        printf("\n");
    }
}

C

// C program to print the inverted full pyramid pattern of
// numbers
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop for printing all rows
    for (int i = 0; i < rows; i++) {

        // first inner loop for printing leading white
        // spaces
        for (int j = 0; j < 2 * i; j++) {
            printf(" ");
        }

        // second inner loop for printing numbers
        for (int k = 0; k < 2 * (rows - i) - 1; k++) {
            printf("%d ", k + 1);
        }
        printf("\n");
    }
}

C

// C program to print the inverted full pyramid pattern of
// alphabets
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop for printing all rows
    for (int i = 0; i < rows; i++) {

        // first inner loop for printing leading white
        // spaces
        for (int j = 0; j < 2 * i; j++) {
            printf(" ");
        }

        // second inner loop for printing alphabets
        for (int k = 0; k < 2 * (rows - i) - 1; k++) {
            printf("%c ", 'A' + k);
        }
        printf("\n");
    }
}

Output

* * * * * * * * *   |   1 2 3 4 5 6 7 8 9   |   A B C D E F G H I
  * * * * * * *     |     1 2 3 4 5 6 7     |     A B C D E F G
    * * * * *       |       1 2 3 4 5       |       A B C D E
      * * *         |         1 2 3         |         A B C
        *           |           1           |           A

Time Complexity: O(rows*rows) as nested for loop is being run.
Auxiliary Space: O(1) as no extra space has been used.

7. Rhombus Pattern in C

The Rhombus pattern is similar to the square pattern, just that we have to add spaces before each line and their count decreases progressively with rows.

C

// C Program to print the rhombus pattern using * star
#include <stdio.h>

int main()
{
    int rows = 5;

    // first outer loop to iterate through each row
    for (int i = 0; i < rows; i++) {

        // first inner loop to print white spaces
        for (int j = 0; j < rows - i - 1; j++) {
            printf(" ");
        }

        // second inner loop to print * star in each row
        for (int k = 0; k < rows; k++) {
            printf("* ");
        }
        printf("\n");
    }
    return 0;
}

C

// C Program to print the rhombus pattern using numbers
#include <stdio.h>

int main()
{
    int rows = 5;

    // first outer loop to iterate through each row
    for (int i = 0; i < rows; i++) {

        // first inner loop to print white spaces
        for (int j = 0; j < rows - i - 1; j++) {
            printf(" ");
        }

        // second inner loop to print number in each row
        for (int k = 0; k < rows; k++) {
            printf("%d ", k + 1);
        }
        printf("\n");
    }
    return 0;
}

C

// C Program to print the rhombus pattern using alphabet
#include <stdio.h>

int main()
{
    int rows = 5;

    // first outer loop to iterate through each row
    for (int i = 0; i < rows; i++) {

        // first inner loop to print white spaces
        for (int j = 0; j < rows - i - 1; j++) {
            printf(" ");
        }

        // second inner loop to print alphabet in each row
        for (int k = 0; k < rows; k++) {
            printf("%c ", k + 'A');
        }
        printf("\n");
    }
    return 0;
}

Output

    * * * * *   |       1 2 3 4 5   |       A B C D E
   * * * * *    |      1 2 3 4 5    |      A B C D E
  * * * * *     |     1 2 3 4 5     |     A B C D E
 * * * * *      |    1 2 3 4 5      |    A B C D E
* * * * *       |   1 2 3 4 5       |   A B C D E

8. Diamond Pattern in C

The Diamond Pattern is obtained by joining the Full Pyramid and Inverted Full Pyramid Pattern by their bases. We can also print this pattern using any character.

Example:

C

// C Program to print diamond pattern using star *
#include <stdio.h>
int main()
{
    int n = 5;

    // first outer loop to iterate through each row
    for (int i = 0; i < 2 * n - 1; i++) {

        // assigning values to the comparator according to
        // the row number
        int comp;
        if (i < n) {
            comp = 2 * (n - i) - 1;
        }
        else {
            comp = 2 * (i - n + 1) + 1;
        }

        // first inner loop to print leading whitespaces
        for (int j = 0; j < comp; j++) {
            printf(" ");
        }

        // second inner loop to print stars *
        for (int k = 0; k < 2 * n - comp; k++) {
            printf("* ");
        }
        printf("\n");
    }
    return 0;
}

C

// C Program to print diamond pattern using numbers
#include <stdio.h>
int main()
{
    int n = 5;

    // first outer loop to iterate through each row
    for (int i = 0; i < 2 * n - 1; i++) {

        // assigning values to the comparator according to
        // the row number
        int comp;
        if (i < n) {
            comp = 2 * (n - i) - 1;
        }
        else {
            comp = 2 * (i - n + 1) + 1;
        }

        // first inner loop to print leading whitespaces
        for (int j = 0; j < comp; j++) {
            printf(" ");
        }

        // second inner loop to print number
        for (int k = 0; k < 2 * n - comp; k++) {
            printf("%d ", k + 1);
        }
        printf("\n");
    }
    return 0;
}

C

// C Program to print diamond pattern using alphabets
#include <stdio.h>
int main()
{
    int n = 5;

    // first outer loop to iterate through each row
    for (int i = 0; i < 2 * n - 1; i++) {

        // assigning values to the comparator according to
        // the row number
        int comp;
        if (i < n) {
            comp = 2 * (n - i) - 1;
        }
        else {
            comp = 2 * (i - n + 1) + 1;
        }

        // first inner loop to print leading whitespaces
        for (int j = 0; j < comp; j++) {
            printf(" ");
        }

        // second inner loop to print alphabet
        for (int k = 0; k < 2 * n - comp; k++) {
            printf("%c ", k + 'A');
        }
        printf("\n");
    }
    return 0;
}

Output

        *           |           1           |           A
      * * *         |         1 2 3         |         A B C
    * * * * *       |       1 2 3 4 5       |       A B C D E
  * * * * * * *     |     1 2 3 4 5 6 7     |     A B C D E F G
* * * * * * * * *   |   1 2 3 4 5 6 7 8 9   |   A B C D E F G H I
  * * * * * * *     |     1 2 3 4 5 6 7     |     A B C D E F G
    * * * * *       |       1 2 3 4 5       |       A B C D E
      * * *         |         1 2 3         |         A B C
        *           |           1           |           A

9. Hourglass Pattern in C

Hourglass Pattern is a combination of the inverted full pyramid and full pyramid patterns but in the opposite sense to that of diamond pattern. Here we join them using their tip.

C

// C Program to print hourglass pattern using star *
#include <stdio.h>
int main()
{
    int rows = 5;

    // first outer loop to iterate each row
    for (int i = 0; i < 2 * rows - 1; i++) {

        // assigning comparator
        int comp;
        if (i < rows) {
            comp = 2 * i + 1;
        }
        else {
            comp = 2 * (2 * rows - i) - 3;
        }

        // first inner loop to print leading spaces
        for (int j = 0; j < comp; j++) {
            printf(" ");
        }

        // second inner loop to print star *
        for (int k = 0; k < 2 * rows - comp; k++) {
            printf("* ");
        }
        printf("\n");
    }
    return 0;
}

C

// C Program to print hourglass pattern using numbers
#include <stdio.h>
int main()
{
    int rows = 5;

    // first outer loop to iterate each row
    for (int i = 0; i < 2 * rows - 1; i++) {

        // assigning comparator
        int comp;
        if (i < rows) {
            comp = 2 * i + 1;
        }
        else {
            comp = 2 * (2 * rows - i) - 3;
        }

        // first inner loop to print leading spaces
        for (int j = 0; j < comp; j++) {
            printf(" ");
        }

        // second inner loop to print number
        for (int k = 0; k < 2 * rows - comp; k++) {
            printf("%d ", k + 1);
        }
        printf("\n");
    }
    return 0;
}

C

// C Program to print hourglass pattern using alphabets
#include <stdio.h>
int main()
{
    int rows = 5;

    // first outer loop to iterate each row
    for (int i = 0; i < 2 * rows - 1; i++) {

        // assigning comparator
        int comp;
        if (i < rows) {
            comp = 2 * i + 1;
        }
        else {
            comp = 2 * (2 * rows - i) - 3;
        }

        // first inner loop to print leading spaces
        for (int j = 0; j < comp; j++) {
            printf(" ");
        }

        // second inner loop to print alphabets
        for (int k = 0; k < 2 * rows - comp; k++) {
            printf("%c ", k + 'A');
        }
        printf("\n");
    }
    return 0;
}

Output

* * * * * * * * *   |   1 2 3 4 5 6 7 8 9   |   A B C D E F G H I
  * * * * * * *     |     1 2 3 4 5 6 7     |     A B C D E F G
    * * * * *       |       1 2 3 4 5       |       A B C D E
      * * *         |         1 2 3         |         A B C 
        *           |           1           |           A
      * * *         |         1 2 3         |         A B C
    * * * * *       |       1 2 3 4 5       |       A B C D E
  * * * * * * *     |     1 2 3 4 5 6 7     |     A B C D E F G
* * * * * * * * *   |   1 2 3 4 5 6 7 8 9   |   A B C D E F G H I

10. Hollow Square Pattern in C

The Hollow Square Pattern is a square with only the boundary lines. The space inside should be empty in this pattern.

C

// C Program to print hollow square pattern using * star
#include <stdio.h>

int main()
{
    int rows = 5;

    // outer loop to iterator through each row
    for (int i = 0; i < rows; i++) {

        // inner loop to print * star in each row
        for (int j = 0; j < rows; j++) {
            // statement to check boundry condition
            if (i > 0 && i < rows - 1 && j > 0
                && j < rows - 1) {
                printf("  ");
            }
            else {
                printf("* ");
            }
        }
        printf("\n");
    }
    return 0;
}

C

// C Program to print hollow square pattern using numbers
#include <stdio.h>

int main()
{
    int rows = 5;

    // outer loop to iterator through each row
    for (int i = 0; i < rows; i++) {

        // inner loop to print number in each row
        for (int j = 0; j < rows; j++) {
            // statement to check boundry condition
            if (i > 0 && i < rows - 1 && j > 0
                && j < rows - 1) {
                printf("  ");
            }
            else {
                printf("%d ", j + 1);
            }
        }
        printf("\n");
    }
    return 0;
}

C

// C Program to print hollow square pattern using alphabet
#include <stdio.h>

int main()
{
    int rows = 5;

    // outer loop to iterator through each row
    for (int i = 0; i < rows; i++) {

        // inner loop to print alphabet in each row
        for (int j = 0; j < rows; j++) {
            // statement to check boundry condition
            if (i > 0 && i < rows - 1 && j > 0
                && j < rows - 1) {
                printf("  ");
            }
            else {
                printf("%c ", j + 'A');
            }
        }
        printf("\n");
    }
    return 0;
}

Output

* * * * *   |   1 2 3 4 5   |   A B C D E
*       *   |   1       5   |   A       E
*       *   |   1       5   |   A       E
*       *   |   1       5   |   A       E
* * * * *   |   1 2 3 4 5   |   A B C D E

11. Hollow Full Pyramid Pattern

In the Hollow Pyramid pattern, we only have to print the boundary of the full pyramid.

C

// C program to print hollow full pyramid using star *
#include <stdio.h>

int main()
{
    int rows = 5;

    // first outer loop to iterate through each loop
    for (int i = 0; i < rows; i++) {

        // first inner loop to print leading whitespaces
        for (int j = 0; j < 2 * (rows - i) - 1; j++) {
            printf(" ");
        }

        // second inner loop to print stars * and inner
        // whitespaces
        for (int k = 0; k < 2 * i + 1; k++) {
            if (k == 0 || k == 2 * i || i == rows - 1) {
                printf("* ");
            }
            else {
                printf("  ");
            }
        }
        printf("\n");
    }
    return 0;
}

C

// C program to print hollow full pyramid using numbers
#include <stdio.h>

int main()
{
    int rows = 5;

    // first outer loop to iterate through each loop
    for (int i = 0; i < rows; i++) {

        // first inner loop to print leading whitespaces
        for (int j = 0; j < 2 * (rows - i) - 1; j++) {
            printf(" ");
        }

        // second inner loop to print numbers and inner
        // whitespaces
        for (int k = 0; k < 2 * i + 1; k++) {
            if (k == 0 || k == 2 * i || i == rows - 1) {
                printf("%d ", k + 1);
            }
            else {
                printf("  ");
            }
        }
        printf("\n");
    }
    return 0;
}

C

// C program to print hollow full pyramid using alphabets
#include <stdio.h>

int main()
{
    int rows = 5;

    // first outer loop to iterate through each loop
    for (int i = 0; i < rows; i++) {

        // first inner loop to print leading whitespaces
        for (int j = 0; j < 2 * (rows - i) - 1; j++) {
            printf(" ");
        }

        // second inner loop to print alphabets and inner
        // whitespaces
        for (int k = 0; k < 2 * i + 1; k++) {
            if (k == 0 || k == 2 * i || i == rows - 1) {
                printf("%c ", k + 'A');
            }
            else {
                printf("  ");
            }
        }
        printf("\n");
    }
    return 0;
}

Output

        *           |           1           |           A
      *   *         |         1   3         |         A   C
    *       *       |       1       5       |       A       E
  *           *     |     1           7     |     A           G
* * * * * * * * *   |   1 2 3 4 5 6 7 8 9   |   A B C D E F G H I

12. Hollow Inverted Full Pyramid Pattern

In this pattern, we print the inverted full pyramid with only boundary elements and remove the inside elements to make it hollow.

Example:

C

// C Program to print hollow full pyramid pattern using star
// *
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop iterating through each row
    for (int i = 0; i < rows; i++) {

        // first inner loop to print leading white space
        for (int j = 0; j < 2 * i + 1; j++) {
            printf(" ");
        }

        // second inner loop to print star* and hollow white
        // space
        for (int k = 0; k < 2 * (rows - i) - 1; k++) {
            if (k == 0 || k == 2 * (rows - i) - 2 || i == 0)
                printf("* ");
            else {
                printf("  ");
            }
        }
        printf("\n");
    }
    return 0;
}

C

// C Program to print hollow full pyramid pattern using
// numbers
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop iterating through each row
    for (int i = 0; i < rows; i++) {

        // first inner loop to print leading white space
        for (int j = 0; j < 2 * i + 1; j++) {
            printf(" ");
        }

        // second inner loop to print number and hollow
        // white space
        for (int k = 0; k < 2 * (rows - i) - 1; k++) {
            if (k == 0 || k == 2 * (rows - i) - 2 || i == 0)
                printf("%d ", k + 1);
            else {
                printf("  ");
            }
        }
        printf("\n");
    }
    return 0;
}

C

// C Program to print hollow full pyramid pattern using
// alphabets
#include <stdio.h>

int main()
{
    int rows = 5;

    // first loop iterating through each row
    for (int i = 0; i < rows; i++) {

        // first inner loop to print leading white space
        for (int j = 0; j < 2 * i + 1; j++) {
            printf(" ");
        }

        // second inner loop to print alphabets and hollow
        // white space
        for (int k = 0; k < 2 * (rows - i) - 1; k++) {
            if (k == 0 || k == 2 * (rows - i) - 2 || i == 0)
                printf("%c ", k + 'A');
            else {
                printf("  ");
            }
        }
        printf("\n");
    }
    return 0;
}

Output

* * * * * * * * *   |   1 2 3 4 5 6 7 8 9   |   A B C D E F G H I
  *           *     |     1           7     |     A           G
    *       *       |       1       5       |       A       E
      *   *         |         1   3         |         A   C
        *           |           1           |           A

13. Hollow Diamond Pattern

This pattern is also similar to the Diamond Pattern but without the inner elements such that it appears hollow inside.

C

// C Program to print the hollow diamond pattern using star
// *
#include <stdio.h>
int main()
{
    int n = 5;

    // first outer loop to iterator through each row
    for (int i = 0; i < 2 * n - 1; i++) {
        // assigning values to the comparator according to
        // the row number
        int comp;
        if (i < n) {
            comp = 2 * (n - i) - 1;
        }
        else {
            comp = 2 * (i - n + 1) + 1;
        }

        // first inner loop to print leading whitespaces
        for (int j = 0; j < comp; j++) {
            printf(" ");
        }

        // second inner loop to print star * and inner
        // whitespaces
        for (int k = 0; k < 2 * n - comp; k++) {
            if (k == 0 || k == 2 * n - comp - 1) {
                printf("* ");
            }
            else {
                printf("  ");
            }
        }
        printf("\n");
    }
    return 0;
}

C

// C Program to print the hollow diamond pattern using
// numbers
#include <stdio.h>
int main()
{
    int n = 5;

    // first outer loop to iterator through each row
    for (int i = 0; i < 2 * n - 1; i++) {
        // assigning values to the comparator according to
        // the row number
        int comp;
        if (i < n) {
            comp = 2 * (n - i) - 1;
        }
        else {
            comp = 2 * (i - n + 1) + 1;
        }

        // first inner loop to print leading whitespaces
        for (int j = 0; j < comp; j++) {
            printf(" ");
        }

        // second inner loop to print number and inner
        // whitespaces
        for (int k = 0; k < 2 * n - comp; k++) {
            if (k == 0 || k == 2 * n - comp - 1) {
                printf("%d ", k + 1);
            }
            else {
                printf("  ");
            }
        }
        printf("\n");
    }
    return 0;
}

C

// C Program to print the hollow diamond pattern using
// alphabet
#include <stdio.h>
int main()
{
    int n = 5;

    // first outer loop to iterator through each row
    for (int i = 0; i < 2 * n - 1; i++) {
        // assigning values to the comparator according to
        // the row number
        int comp;
        if (i < n) {
            comp = 2 * (n - i) - 1;
        }
        else {
            comp = 2 * (i - n + 1) + 1;
        }

        // first inner loop to print leading whitespaces
        for (int j = 0; j < comp; j++) {
            printf(" ");
        }

        // second inner loop to print alphabet and inner
        // whitespaces
        for (int k = 0; k < 2 * n - comp; k++) {
            if (k == 0 || k == 2 * n - comp - 1) {
                printf("%c ", k + 'A');
            }
            else {
                printf("  ");
            }
        }
        printf("\n");
    }
    return 0;
}

Output

        *           |           *           |           A
      *   *         |         *   *         |         A   C
    *       *       |       *       *       |       A       E
  *           *     |     *           *     |     A           G
*               *   |   *               *   |   A               I
  *           *     |     *           *     |     A           G
    *       *       |       *       *       |       A       E
      *   *         |         *   *         |         A   C
        *           |           *           |           A

14. Hollow Hourglass Pattern in C

The hollow hourglass is the pattern in which only the boundary of the hourglass pattern is visible.

C

// C Program to print the hourglass pattern using star *
#include <stdio.h>
int main()
{
    int n = 5;

    // first outer loop to iterate through each row
    for (int i = 0; i < 2 * n - 1; i++) {

        // assigning comparator
        int comp;
        if (i < n) {
            comp = 2 * i + 1;
        }
        else {
            comp = 2 * (2 * n - i) - 3;
        }

        // first inner loop to print leading whitespaces
        for (int j = 0; j < comp; j++) {
            printf(" ");
        }

        // second inner loop to print star * and inner
        // whitespaces
        for (int k = 0; k < 2 * n - comp; k++) {
            if (k == 0 || k == 2 * n - comp - 1 || i == 0
                || i == 2 * n - 2) {
                printf("* ");
            }
            else {
                printf("  ");
            }
        }
        printf("\n");
    }
    return 0;
}

C

// C Program to print the hourglass pattern using numbers
#include <stdio.h>
int main()
{
    int n = 5;

    // first outer loop to iterate through each row
    for (int i = 0; i < 2 * n - 1; i++) {

        // assigning comparator
        int comp;
        if (i < n) {
            comp = 2 * i + 1;
        }
        else {
            comp = 2 * (2 * n - i) - 3;
        }

        // first inner loop to print leading whitespaces
        for (int j = 0; j < comp; j++) {
            printf(" ");
        }

        // second inner loop to print number and inner
        // whitespaces
        for (int k = 0; k < 2 * n - comp; k++) {
            if (k == 0 || k == 2 * n - comp - 1 || i == 0
                || i == 2 * n - 2) {
                printf("%d ", k + 1);
            }
            else {
                printf("  ");
            }
        }
        printf("\n");
    }
    return 0;
}

C

// C Program to print the hourglass pattern using alphabets
#include <stdio.h>
int main()
{
    int n = 5;

    // first outer loop to iterate through each row
    for (int i = 0; i < 2 * n - 1; i++) {

        // assigning comparator
        int comp;
        if (i < n) {
            comp = 2 * i + 1;
        }
        else {
            comp = 2 * (2 * n - i) - 3;
        }

        // first inner loop to print leading whitespaces
        for (int j = 0; j < comp; j++) {
            printf(" ");
        }

        // second inner loop to print alphabets and inner
        // whitespaces
        for (int k = 0; k < 2 * n - comp; k++) {
            if (k == 0 || k == 2 * n - comp - 1 || i == 0
                || i == 2 * n - 2) {
                printf("%c ", k + 'A');
            }
            else {
                printf("  ");
            }
        }
        printf("\n");
    }
    return 0;
}

Output

* * * * * * * * *   |   1 2 3 4 5 6 7 8 9    |   A B C D E F G H I
  *           *     |     1           7      |     A           G
    *       *       |       1       5        |       A       E
      *   *         |         1   3          |         A   C
        *           |           1            |           A
      *   *         |         1   3          |         A   C
    *       *       |       1       5        |       A       E
  *           *     |     1           7      |     A           G
* * * * * * * * *   |   1 2 3 4 5 6 7 8 9    |   A B C D E F G H I

15. Floyd’s Triangle in C

In Floyd’s Triangle pattern, instead of starting the sequence of the numbers from 1 in each row, we print consecutive natural numbers. We can also print this pattern for alphabet sequence.

Example:

C

// C Program to print the Floyd's Triangle
#include <stdio.h>

int main()
{
    int rows = 4;
    int n = 1;

    // outer loop to print all rows
    for (int i = 0; i < rows; i++) {

        // innter loop to print abphabet in each row
        for (int j = 0; j <= i; j++) {
            printf("%d ", n++);
        }
        printf("\n");
    }
    return 0;
}

C

// C Program to print the Floyd's Triangle of Alphabets
#include <stdio.h>

int main()
{
    int rows = 4;
    char n = 'A';

    // outer loop to print all rows
    for (int i = 0; i < rows; i++) {

        // innter loop to print abphabet in each row
        for (int j = 0; j <= i; j++) {
            printf("%c ", n++);
        }
        printf("\n");
    }
    return 0;
}

Output

1          |   A
2 3        |   B C
4 5 6      |   D E F
7 8 9 10   |   G H I J

16. Pascal’s Triangle in C

A Pascal’s Triangle is a triangular array of binomial coefficients where the n^th row contains the binomial coefficients ⁿC₀, ⁿC₁, ⁿC₂, ……. ⁿC_n. The following example demonstrates one of the methods using which we can print Pascal’s Triangle Pattern.

Example:

C

// C program to print the pascal's triangle pattern
#include <stdio.h>

int main()
{
    int rows = 5;

    // outer loop for rows
    for (int i = 1; i <= rows; i++) {

        // inner loop 1 for leading white spaces
        for (int j = 0; j < rows - i; j++) {
            printf(" ");
        }

        int C = 1; // coefficient

        // inner loop 2 for printing numbers
        for (int k = 1; k <= i; k++) {
            printf("%d ", C);
            C = C * (i - k) / k;
        }
        printf("\n");
    }
    return 0;
}

Output

    1 
   1 1 
  1 2 1 
 1 3 3 1 
1 4 6 4 1 

To know more about Pascal’s Triangle, refer to this article – Pascal’s Triangle