* * Checking for cases where no of quadrilaterals = 1 or 3 * *
int check = 0 ; if ( doIntersect ( p1 , p2 , p3 , p4 ) ) check = 1 ; if ( doIntersect ( p1 , p3 , p2 , p4 ) ) check = 1 ; if ( doIntersect ( p1 , p2 , p4 , p3 ) ) check = 1 ; if ( check == 0 ) return 3 ; return 1 ; }