text: Computing the x ^ 2 + y ^ 2 for each given points and sorting them .
code: function preprocess ( p , x , y , n ) { for ( let i = 0 ; i < n ; i ++ ) p [ i ] = x [ i ] * x [ i ] + y [ i ] * y [ i ] ; p . sort ( function ( a , b ) { return a - b ; } ) ; }