苗火 Nicholas

Description

Did you know that if you draw a circle that fills the screen on your 1080p high definition display, almost a million pixels are lit? That's a lot of pixels! But do you know exactly how many pixels are lit? Let's find out!

Assume that our display is set on a Cartesian grid where every pixel is a perfect unit square. For example, one pixel occupies the area of a square with corners (0,0) and (1,1). A circle can be drawn by specifying its center in grid coordinates and its radius. On our display, a pixel is lit if any part of it is covered by the circle being drawn; pixels whose edge or corner are just touched by the circle, however, are not lit.

Your job is to compute the exact number of pixels that are lit when a circle with a given position and radius is drawn.

Input

The input consists of several test cases, each on a separate line. Each test case consists of three integers, x,y, and r(1≤x,y,r≤1,000,000), specifying respectively the center (x,y) and radius of the circle drawn. Input is followed by a single line with x = y = r = 0, which should not be processed.

Output

For each test case, output on a single line the number of pixels that are lit when the specified circle is drawn. Assume that the entire circle will fit within the area of the display.

#include <stdio.h>
#include <math.h>

void main(){
        long long x,y,r;
        long long i,j,sum,h;
        while(scanf("%lld %lld %lld", &x, &y, &r) != EOF){
                if(x == 0 && y == 0 && r == 0){
                        break;
                }
                sum = 0;
                for(i=0; i<r; i++){
                        j = (r*r - i*i);
                        h = (long long)ceil(sqrt((double)j));
                        sum += h;
                }
                printf("%lld\n", sum*4);
        };
}