C program to print hollow inverted pyramid star pattern

C program to print hollow inverted pyramid star pattern

October 7, 2019

In this article, I will show you, How to write a C program to print hollow inverted pyramid star pattern series of n rows using for loop. How to print hollow inverted pyramid star pattern in C programming. Here, one thing is important to know that the rows of the pyramid.

Logic to C program to print hollow inverted pyramid star pattern:

  • Enter the row value for the equilateral triangle.
  • Here I have used three loops one is the outer loop to change the line and two inner loops to print star and space.
  • The outer loop iterate N times and print a newline after completing the inner loop.
  • First inner loop print the space x to (N-1)(where N is the row number and x is the current row number).
  • The second inner loop print the star at xth or last column or for last row. It iterates from 1 to ( ( N* 2) – ( (2*x) -1) ) times.

See the, C program to print hollow reverse pyramid star pattern:

 

#include <stdio.h>

int main()
{
    int x = 0,y = 0;
    unsigned int rows = 0;

    printf("Enter the number of rows = ");
    scanf("%u",&rows);

    for(x=1; x<=rows; ++x)
    {
        // Print spaces
        for(y=1; y<=x; ++y)
        {
            printf(" ");
        }
        // Print star/
        for(y =1; y <=((rows*2)-((2*x)-1)); ++y)
        {
            if(x==1 || y==1 || y==((rows*2)-((2*x)-1)))
            {
                printf("*");
            }
            else
            {
                printf(" ");
            }
        }
        // Print new line
        printf("\n");
    }
    return 0;
}

Output:

print hollow inverted pyramid star pattern

Code Analysis:

It asks the user to enter the row for the hollow reverse pyramid (equilateral triangle).

printf("Enter the number of rows = ");
scanf("%u",&rows);

 

First, inner loop print space x to (N-1) times.

// Print spaces
for(y=1; y<=x; ++y)
{
    printf(" ");
}

 

The second inner loop print the star at x-th position or last column or for the first row otherwise it prints space.

// Print star
for(y =1; y <= ((rows*2)-((2*x)-1)); ++y)
{
    if(x==1 || y==1 || y==((rows*2)-((2*x)-1)))
    {
        printf("*");
    }
    else
    {
        printf(" ");
    }
}

 

The outer loop print the newline after each iteration of the inner loops.

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