Draw a circle without floating point arithmetic

Given a radius of a circle, draw the circle without using floating point arithmetic.

Following program uses a simple concept. Let the radius of the circle be r. Consider a square of size (2r+1)*(2r+1) around the circle to be drawn. Now walk through every point inside the square. For every every point (x,y), if (x, y) lies inside the circle (or x^2+ y^2 < r^2), then print it, otherwise print space.

#include <stdio.h>

void drawCircle(int r)
{
    // Consider a rectangle of size N*N
    int N = 2*r+1;

    int x, y;  // Coordinates inside the rectangle

    // Draw a square of size N*N.
    for (int i = 0; i < N; i++)
    {
        for (int j = 0; j < N; j++)
        {
            // Start from the left most corner point
            x = i-r;
            y = j-r;

            // If this point is inside the circle, print it
            if (x*x + y*y <= r*r+1 )
                printf(".");
            else // If outside the circle, print space
                printf(" ");
            printf(" ");
        }
        printf("\n");
    }
}

// Driver Program to test above function
int  main()
{
    drawCircle(8);
    return 0;
}

Output:

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