Programa para imprimir patrones circulares

Dado un número entero positivo n, es decir, el radio del círculo, imprima un círculo usando estrellas. 
Ejemplos: 
 

Input : n = 3
Output :
  ***  
 *   * 
*     *
*     *
*     *
 *   * 
  ***

Input : n = 6
Output :
    *****    
  **     **  
 **       ** 
 *         * 
*           *
*           *
*           *
*           *
*           *
 *         * 
 **       ** 
  **     **  
    *****    

// C++ implementation to print circle pattern
#include <bits/stdc++.h>
using namespace std;
 
// function to print circle pattern
void printPattern(int radius) {
 
  // dist represents distance to the center
  float dist;
 
  // for horizontal movement
  for (int i = 0; i <= 2 * radius; i++) {
 
    // for vertical movement
    for (int j = 0; j <= 2 * radius; j++) {
      dist = sqrt((i - radius) * (i - radius) +
                  (j - radius) * (j - radius));
 
      // dist should be in the range (radius - 0.5)
      // and (radius + 0.5) to print stars(*)
      if (dist > radius - 0.5 && dist < radius + 0.5)
        cout << "*";
      else
        cout << " ";     
    }
 
    cout << "\n";
  }
}
 
// Driver Code
int main() {
  int radius = 6;
  printPattern(radius);
  return 0;
}

// Java implementation to print circle pattern
 
class GFG {
     
// function to print circle pattern
static void printPattern(int radius) {
 
    // dist represents distance to the center
    double dist;
 
    // for horizontal movement
    for (int i = 0; i <= 2 * radius; i++) {
 
    // for vertical movement
    for (int j = 0; j <= 2 * radius; j++) {
        dist = Math.sqrt((i - radius) * (i - radius) +
                         (j - radius) * (j - radius));
 
        // dist should be in the range (radius - 0.5)
        // and (radius + 0.5) to print stars(*)
        if (dist > radius - 0.5 && dist < radius + 0.5)
        System.out.print("*");
        else
        System.out.print(" ");
    }
 
    System.out.print("\n");
    }
}
 
// Driver code
public static void main(String[] args)
{
    int radius = 6;
    printPattern(radius);
}
}
 
// This code is contributed by Anant Agarwal.

# Python implementation
# to print circle pattern
 
import math
 
# function to print circle pattern
def printPattern(radius):
     
    # dist represents distance to the center
    # for horizontal movement
    for i in range((2 * radius)+1):
  
        # for vertical movement
        for j in range((2 * radius)+1):
             
            dist = math.sqrt((i - radius) * (i - radius) +
                  (j - radius) * (j - radius))
  
            # dist should be in the
            # range (radius - 0.5)
            # and (radius + 0.5) to print stars(*)
            if (dist > radius - 0.5 and dist < radius + 0.5):
                print("*",end="")
            else:
                print(" ",end="")     
     
  
        print()
   
# Driver code
 
radius = 6
printPattern(radius)
 
# This code is contributed
# by Anant Agarwal.

// C# implementation to print circle pattern
using System;
 
class GFG {
     
    // function to print circle pattern
    static void printPattern(int radius) {
     
        // dist represents distance to the center
        double dist;
     
        // for horizontal movement
        for (int i = 0; i <= 2 * radius; i++) {
     
            // for vertical movement
            for (int j = 0; j <= 2 * radius; j++) {
                dist = Math.Sqrt((i - radius) *
                        (i - radius) + (j - radius)
                                    * (j - radius));
         
                // dist should be in the range
                // (radius - 0.5) and (radius + 0.5)
                // to print stars(*)
                if (dist > radius - 0.5 &&
                               dist < radius + 0.5)
                    Console.Write("*");
                else
                    Console.Write(" ");
            }
         
            Console.WriteLine("");
        }
    }
     
    // Driver code
    public static void Main()
    {
        int radius = 6;
         
        printPattern(radius);
    }
}
 
// This code is contributed by vt_m.

<?php
// PHP implementation to print
// circle pattern
 
// Function to print circle pattern
function printPattern($radius)
    {
     
    // dist represents distance
    // to the center
    $dist = 0.0;
     
    // for horizontal movement
    for ($i = 0; $i <= 2 * $radius; $i++)
    {
     
        // for vertical movement
        for ($j = 0; $j <= 2 * $radius; $j++)
        {
            $dist = sqrt(($i - $radius) *
                         ($i - $radius) +
                         ($j - $radius) *
                         ($j - $radius));
         
            // dist should be in the range
            // (radius - 0.5) and (radius + 0.5)
            // to print stars(*)
            if ($dist > $radius - 0.5 &&
                 $dist < $radius + 0.5)
                echo "*";
                 
            else
                echo " ";
        }
        echo "\n";
    }
}
 
// Driver Code
$radius = 6;
printPattern($radius);
 
// This code is contributed by Mithun Kumar
?>

<script>
 
// JavaScript implementation to print circle pattern
 
// function to print circle pattern
function printPattern(radius)
{
// dist represents distance to the center
        var dist = parseFloat(0);
 
        // for horizontal movement
        for (var i = 0; i <= 2 * radius; i++)
        { 
          // for vertical movement
          for (var j = 0; j <= 2 * radius; j++)
          {
            dist = Math.sqrt(
              (i - radius) * (i - radius) +
              (j - radius) * (j - radius)
            );
 
            // dist should be in the range (radius - 0.5)
            // and (radius + 0.5) to print stars(*)
            if (dist > radius - 0.5 && dist < radius + 0.5)
            document.write("*");
            else
            document.write("  ");
          }
 
          document.write("<br>");
        }
      }
 
      // Driver Code
       
      var radius = 6;
  
      printPattern(radius);
       
    </script>

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