checks whether the point crosses the convex hull or not
def orientation ( a , b , c ) : NEW_LINE INDENT res = ( ( b [ 1 ] - a [ 1 ] ) * ( c [ 0 ] - b [ 0 ] ) - ( c [ 1 ] - b [ 1 ] ) * ( b [ 0 ] - a [ 0 ] ) ) NEW_LINE if ( res == 0 ) : NEW_LINE INDENT return 0 ; NEW_LINE DEDENT if ( res > 0 ) : NEW_LINE INDENT return 1 ; NEW_LINE DEDENT return - 1 ; NEW_LINE DEDENT