Poj Solution 2954

http://poj.org/problem?id=2954

//* @author: ccQ.SuperSupper
import java.io.*;
import java.util.*;
class Point{
    int x,y;
}
public class Main {
    
    static Point triangle[] = new Point[3];
    static int GCD(int a,int b){
        if(b==0) return a;
        return GCD(b,a%b);
    }
    static int area(Point a,Point b,Point c){
        return (b.x-a.x)*(c.y-a.y) - (b.y-a.y)*(c.x-a.x);
    }
    static int solve(){
        int ans=0,i=0;
        int area = area(triangle[0],triangle[1],triangle[2]);
        i += node_in_line(triangle[0],triangle[1]);
        i += node_in_line(triangle[1],triangle[2]);
        i += node_in_line(triangle[0],triangle[2]);
        if(area< 0) area = -area;
        ans = (area-i+2)/2;
        return ans;
    }
    static int node_in_line(Point a,Point b){
        int x,y;
        x = a.x-b.x;
        if(x< 0) x = -x;
        y = a.y-b.y;
        if(y< 0) y = -y;
        if(x==0) return y;
        if(y==0) return x;
        return GCD(x,y);
    }
    public static void main(String[]args) throws Exception{
        
        int i,j;
        //Scanner cin = new Scanner(new FileInputStream("input.txt"));
        Scanner cin = new Scanner(System.in);
        for(i=0;i< 3;++i) triangle[i] = new Point();
        while(true){
            for(i=j=0;i< 3;++i){
                triangle[i].x = cin.nextInt();
                triangle[i].y = cin.nextInt();
                if(triangle[i].x!=0) j=1;
                if(triangle[i].y!=0) j=1;
            }
            if(j==0) break;
            
            System.out.println(solve());
        }
    }
}