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 )
else // If outside the circle, print space
printf(" ");
printf(" ");

// Driver Program to test above function
int main()
return 0;


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