CCW

int ccw(int x1, int y1, int x2, int y2, int x3, int y3) {
 int temp = x1*y2+x2*y3+x3*y1;
 temp = temp - y1*x2-y2*x3-y3*x1;
 if (temp > 0) {
     return 1;
 } else if (temp < 0) {
     return -1;
 } else {
     return 0;
 }
}