1 #include <iostream> 2 #include <cmath> 3 #include <iomanip> 4 using namespace std; 5  6 double Abs( double x ) 7 { 8     return x > 0 ? x : -x; 9 }10 11 int main()12 {13     cin.sync_with_stdio(false);14     int t , n;15     double t1 , x1 , y1 , t2 , x2 , y2 , var , ans;16     cin >> t;17     while( t-- )18     {19         cin >> n;20         cin >> t1 >> x1 >> y1;21         ans = 0;22         for( int i = 2 ; i<=n ; i++ )23         {24             cin >> t2 >> x2 >> y2;25             var = sqrt( Abs(x2-x1)*Abs(x2-x1) + Abs(y2-y1)*Abs(y2-y1) ) / Abs(t2-t1);26             ans = max( var , ans );27             t1 = t2;28             x1 = x2;29             y1 = y2;30         }31         cout << setiosflags(ios::fixed);32         cout << setprecision(10) << ans << endl;33     }34     return 0;35 }