Counting frequency of each x and y coordinates
if ( x_axis . containsKey ( p [ i ] [ 0 ] ) ) x_axis . put ( p [ i ] [ 0 ] , x_axis . get ( p [ i ] [ 0 ] ) + 1 ) ; else x_axis . put ( p [ i ] [ 0 ] , 1 ) ; if ( y_axis . containsKey ( p [ i ] [ 1 ] ) ) y_axis . put ( p [ i ] [ 1 ] , y_axis . get ( p [ i ] [ 1 ] ) + 1 ) ; else y_axis . put ( p [ i ] [ 1 ] , 1 ) ; }