Return distance between the centers
long double dis ( ll x1 , ll y1 , ll x2 , ll y2 ) { return sqrt ( ( x1 - x2 ) * ( x1 - x2 ) + ( y1 - y2 ) * ( y1 - y2 ) ) ; } bool check ( node c1 , node c2 , int k ) { long double min = 0 ; long double max = 0 ;