C++ program to print hollow pyramid (Equilateral triangle) star pattern

Example

Input :

 Input rows: 5 

Output :

     *
    * *
   *   *
  *     *
 *********

Required Knowledge

Basic C++ programming, if-else, for loop, nested loop

Program to print hollow pyramid star pattern

include <iostream>
using namespace std;

int main()
{
     int i, j, rows;
     
     /* Input rows to print from user */
     cout<<"Enter number of rows : ";
     cin>>rows;

     for(i=1; i<=rows; i++) 
     {
          /* Print trailing spaces */
          for(j=i; j<rows; j++)
          {
               cout<<" ";
          }

          /* Print hollow pyramid */
          for(j=1; j<=(2*i-1); j++)
          {
               /*
                    * Print star for last row (i==rows),
                    * first column(j==1) and for          
                    * last column (j==(2*i-1)).
               */
               if(i==rows || j==1 || j==(2*i-1))
               {
                    cout<<"*";
               }

               else
               {
                    cout<<" ";
               }
         }

         /* Move to next line */
         cout<<"\n";
     }
     return 0;
}