Coding Pyramid Patterns is easier than you think

Basics

Learning how to print a row & a column is very important for any pattern program.

1.Printing a row

Printing a new line so that every row is printed in a new line

for(int row=1;row<=n;row++){


    printf("\n");
}

2.Reverse printing a row

Printing a row starting from n till 1 while decrementing the row number.

for(int row=n;row>=1;row--){

    printf("\n");
}

3.Printing a column

Inside each row, we will print multiple columns. To do that we need to print columns inside of each row.

// outer loop to print rows
for(int row=n;row>=1;row--){

    // inner loop to print columns
    for(int col=1;col<=n;col++){
        printf("*");
    }

    printf("\n");
}

// this will print a square filled with stars
// * * * *
// * * * *
// * * * *
// * * * *

4.Printing as many columns as the row number

Example : 3 columns for 3rd row , 5 columns for 5th row , 1 column for 1st row.
So, for that we need to print columns till number of row running. Meaning , if iteration for row 2 is running then the columns loop should run till 2 times.

// inner loop to print columns
for(int col=1;col<=row;col++){
    printf("*");
}

// this will print a triangle filled with stars
// * 
// * * 
// * * * 
// * * * *

Triangles

Right-Angled Triangle #1

The simplest of all. This is the base of all the algorithms later in this article. So here , we print as many columns as the row number. So for example : 3 rows for 3rd row , 5 columns for 5th row like that.
(Optional) You can add some space after * to make it look pretty !

Steps :

Print Rows till n elements.
Print columns till row number.

// outer loop to print rows
for(int row=1;row<=n;row++){

    // inner loop to print columns
    for(int col=1;col<=row;col++){
        printf("* "); 
    }

    printf("\n");
}

Reverse of Right-Angled Triangle #1

This is just the reverse of the 1st triangle. Knowing this will later come handy when we print the reverse of any other triangles as well as shapes like diamond , hourglass.

Steps :

Print the Right Angled Triangle #1
Reverse the rows

// outer loop reversed
for(int row=n;row>=1;row--){

    for(int col=1;col<=row;col++){
        printf("* "); 
    }

    printf("\n");
}

Isosceles Triangle & Importance of Spaces

This is very important program. Once you understand this, you will easily create diamond & hourglass shapes. This is where we introduce the concepts of leading spaces.

Leading spaces : These are the spaces before the stars (leading means before). This space shifts the triangle.

Trailing spaces : These are the spaces after each star (trailing means after). This space spaces the triangle.

Isosceles triangle with leading & trailing spaces where n = 5

What happens actually is ?

for the 1st row : 4 spaces (blue circles) & then 1 star with trailing space (violet circles).
for the 2nd row : 3 spaces & then 2 stars with trailing spaces in between each of them.
for the 3rd row : 2 spaces & then 3 stars with trailing spaces in between each of them.
for nth row : n-row spaces & n stars with trailing spaces for each of them.

So , the 1st row has 6 columns (4 leading spaces + 1 star + 1 trailing space) whereas 5th row (last row) has 10 columns(0 leading spaces + 5 stars with 5 trailing spaces in between them) . That means 5th column is at the middle of the figure. So the 1st row's star is at the middle of the figure.

Both the leading & trailing spaces gives the look of isosceles triangle!

Steps to print ▲ :

Print the Right-Angled Triangle #1
Before printing columns, print the leading spaces till n-row times.
Then include spaces after each star.

for (int row=1;row<=n;row++){

    // print leading spaces
    for (int spaces=1;spaces <= n-row; spaces++){
         printf(" "); // single space
    }

    // print stars
    for (int col=1; col <= row; col++){
        printf("* "); // trailing space added
    }

    // create new row
    printf("\n");
    }

Right Angled Triangle #2

Here also space plays a very important role. If you double the amount of leading spaces , then the triangle looks like the above image.

Steps to print ◢ :

Print the isosceles triangle
Double the amount of leading spaces.

for (int row=1;row<=n;row++){

    // print leading spaces
    for (int spaces=1;spaces <= n-row; spaces++){
         printf("  "); // double space
    }

    // print stars
    for (int col=1; col <= row; col++){
        printf("* "); // trailing space added
    }

    // create new row
    printf("\n");
    }

Reverse of Isosceles Triangle & Right-Angled Triangle #2 : Just reverse the rows using the steps I showed above.

Combining of the above triangles to create different patterns

The above base triangles are enough to combine them to print multiple complex patterns.

Right Pascals Triangle

Steps :

Print the right-angled triangle #1 ◣
Print another ◣ & then reverse the rows to reverse it ◤
Remove the last row from any triangle to make it look prettier

#include <stdio.h>

int main()
{
    int n = 6;

    for(int row=1;row<=n;row++){

        for(int col=1;col<=row;col++){
            printf("*");
        }

        printf("\n");
    }

    for(int row=n-1;row>=1;row--){

        for(int col=1;col<=row;col++){
            printf("*");
        }

        printf("\n");
    }

    return 0;
}

K Pattern

Steps :

Print the reverse of right-angled triangle #1 ◤
Print the right-angled triangle #1 ◣
Remove the first row from any triangle to make it look prettier

#include <stdio.h>

int main()
{
    int n = 6;

    for(int row=n;row>=1;row--){

        for(int col=1;col<=row;col++){
            printf("*");
        }

        printf("\n");
    }

    for(int row=2;row<=n;row++){

        for(int col=1;col<=row;col++){
            printf("*");
        }

        printf("\n");
    }

    return 0;
}

Diamond

Steps :

Print the isosceles triangle ▲
Print the reverse of isosceles triangle ▼
Remove the last row from any triangle to make it look prettier

#include <stdio.h>

int main()
{
    int n = 6;

    // print ▲
    for (int row=1;row<=n;row++){

        // print leading spaces
        for (int spaces=1;spaces <= n-row; spaces++){
             printf(" "); // single space
        }

        // print stars
        for (int col=1; col <= row; col++){
            printf("* "); // trailing space added
        }

        // create new row
        printf("\n");
    }

    // print ▼
    for (int row=n-1;row>=1;row--){

        // print leading spaces
        for (int spaces=1;spaces <= n-row; spaces++){
             printf(" "); // single space
        }

        // print stars
        for (int col=1; col <= row; col++){
            printf("* "); // trailing space added
        }

        // create new row
        printf("\n");
    }

    return 0;
}

Hourglass

Steps :

Print the reverse of isosceles triangle ▼
Print the isosceles triangle ▲
Remove the 1st row from any triangle

#include <stdio.h>

int main()
{
    int n = 6;

    // print ▼
    for (int row=n;row>=1;row--){

        // print leading spaces
        for (int spaces=1;spaces <= n-row; spaces++){
             printf(" "); // single space
        }

        // print stars
        for (int col=1; col <= row; col++){
            printf("* "); // trailing space added
        }

        // create new row
        printf("\n");
    }

    // print ▲
    for (int row=2;row<=n;row++){

        // print leading spaces
        for (int spaces=1;spaces <= n-row; spaces++){
             printf(" "); // single space
        }

        // print stars
        for (int col=1; col <= row; col++){
            printf("* "); // trailing space added
        }

        // create new row
        printf("\n");
    }



    return 0;
}

Hollow Patterns

This means the 1st & last column of each row as well as all columns of first & last rows will be printed with stars & the middle columns will be printed as spaces.

Hollow Rectangles

Steps :

Print rows & columns till nth element
Check if col is 1st or last OR row is 1st or last
1. if yes , then print *
2. else , print space

#include <stdio.h>

int main()
{
    int n =5;
    for (int row =1; row <= n; row++)
    {
       for (int col =1; col <= n; col++)
        {
            if(row==1 || col==1 || row==n|| col==n)
            {
                printf("*") ;
            }
            else{
                printf(" ") ;
            }
        }
    printf("\n"); 
    }
}

Hollow Triangles

Steps :

Print ◣
Check if col is 1st or last OR row is 1st or last
1. if yes , then print *
2. else , print space

// outer loop to print rows
for(int row=1;row<=n;row++){

    // inner loop to print columns
    for(int col=1;col<=row;col++){
        if(row==1 || row==n || col==1 || col==row)
        printf("* "); 
        else
        printf("  "); //double spaces
    }

    printf("\n");
}

Hollow Diamond

Steps :

Print 🔷 like the way shown above
Then for each time printing columns Check if col is 1st or last
1. if yes , then print *
2. else , print space

#include <stdio.h>

int main()
{
    int n = 6;

    // print ▲
    for (int row=1;row<=n;row++){

        // print leading spaces
        for (int spaces=1;spaces <= n-row; spaces++){
             printf(" "); // single space
        }

        // print stars
        for (int col=1; col <= row; col++){
            if(col==1 || col==row)
                printf("* "); 
            else
                printf("  "); //double spaces
        }

        // create new row
        printf("\n");
    }

    // print ▼
    for (int row=n-1;row>=1;row--){

        // print leading spaces
        for (int spaces=1;spaces <= n-row; spaces++){
             printf(" "); // single space
        }

        // print stars
        for (int col=1; col <= row; col++){
             if(col==1 || col==row)
                printf("* "); 
            else
                printf("  "); //double spaces
        }

        // create new row
        printf("\n");
    }

    return 0;
}

Conclusion

You can try to print more Pyramid patterns after understanding the concepts. Here is a simple challenge for you! Can you print Hollow Hourglass ?
Do let me know your feedback on this article & how did you solve this challenge ..

Coding Pyramid Patterns is easier than you think

This is a comprehensive guide to pyramid pattern programs with simple to understand algorithms.

Table of contents

Basics

Triangles

Right-Angled Triangle #1

Reverse of Right-Angled Triangle #1

Isosceles Triangle & Importance of Spaces

Right Angled Triangle #2

Combining of the above triangles to create different patterns

Right Pascals Triangle

K Pattern

Diamond

Hourglass

Hollow Patterns

Hollow Rectangles

Hollow Triangles

Hollow Diamond

Conclusion