Go: package main

import (
	"fmt"
	"math"
)

func main() {
	var n int
	fmt.Scan(&n)
	for i := 0; i < n; i++ {
		var xa, ya, ra, xb, yb, rb float64
		fmt.Scan(&xa, &ya, &ra, &xb, &yb, &rb)
		// println(xa, ya, ra, xb, yb, rb)
		dis := math.Sqrt((xa-xb)*(xa-xb) + (ya-yb)*(ya-yb))
		if dis + ra < rb {
			fmt.Println(-2)
		} else if dis + rb < ra {
			fmt.Println(2)
		} else if dis > rb + ra {
			fmt.Println(0)
		} else {
			fmt.Println(1)
		}
	}
}

C++: #include <iostream>
#include <cmath>
#include <vector>

int check_intersection(const double ra, const double rb, const double distance){
	if(distance > (ra + rb)){
		return 0;
	}else if(ra > rb){
		return ((distance + rb) < ra) ? 2 : 1;
	}else{
		return ((distance + ra) < rb) ? -2 : 1;
	}
}

int main(){
	int data_set;
	std::cin >> data_set;
	std::vector<double> xa(data_set), ya(data_set), ra(data_set), xb(data_set), yb(data_set), rb(data_set);
	for(int i = 0; i < data_set; ++i){
		std::cin >> xa[i] >> ya[i] >> ra[i] >> xb[i] >> yb[i] >> rb[i];
	}
	double distance;
	for(int i = 0; i < data_set; ++i){
		distance = sqrt(pow(xa.at(i) - xb.at(i), 2) + pow(ya.at(i) - yb.at(i), 2));
		std::cout << check_intersection(ra.at(i), rb.at(i), distance) << std::endl;
	}
	return 0;
}

C++: #include<iostream>
#include<cmath>
#define EPS 0.00000001
using namespace std;

double eq(double x,double y){
  double z=abs(x-y);
  return z<EPS;
}
double di(double x1,double y1,double x2,double y2){
  return sqrt(pow(x1-x2,2.0)+pow(y1-y2,2.0));
}


int n;
double xa,ya,ra,xb,yb,rb;

int main(){
  cin>>n;
  while(n--){
    cin>>xa>>ya>>ra>>xb>>yb>>rb;
    if     (di(xa,ya,xb,yb)+rb<ra)cout<<"2"<<endl;
    else if(di(xa,ya,xb,yb)+ra<rb)cout<<"-2"<<endl;
    else if(di(xa,ya,xb,yb)<=ra+rb)cout<<"1"<<endl;
    else cout<<"0"<<endl;
  }
  return 0;
}

C++: #include <iostream>
#include <math.h>
using namespace std;

int main(){
	int num ;
	cin >> num;
	for(int j = 1;j<= num; j++){
	double x[2],y[2],r[2],r2[2];
	for(int i =0;i<=1;i++){
		cin >> x[i];
		cin >> y[i];
		cin >> r[i];
	}
	double d;
	d = sqrt((x[0]-x[1])*(x[0]-x[1])+(y[0]-y[1])*(y[0]-y[1]));
	if(r[0]+r[1]<d) cout << 0 << endl;
	else if(d > r[0]&& d > r[1]) cout << 1 << endl;
	else if(r[0]<r[1]) cout << -2 << endl;
	else cout << 2 << endl;
	}
	return 0;
}

C++:  
 #include<iostream>
 #include<stdio.h>
 #include<string>
 #include<math.h>
 #include<iomanip>
 #include<algorithm>
 #include<string.h>
 #include<cctype>
 #include<map>
 #include<set>
 #include<vector>
 #include<sstream>
 #include<stack>
 
 using namespace std;
 
 double abs(double x)
 {
   if(x<0) return -x;
   else return x;       
 }
  
 int main()
 {
   int n;
   int result;
   cin>>n;
   double xa,ya,ra,xb,yb,rb;
   while(n--)
   {
     cin>>xa>>ya>>ra>>xb>>yb>>rb;
     double dis=sqrt(pow(yb-ya,2)+pow(xb-xa,2));
     if(dis>ra+rb) result=0;
     else if(dis>abs(ra-rb)) result=1;
     else
     {
       if(dis+ra<=rb) result=-2;
       else if(dis+rb<=ra) result=2;    
     }
     cout<<result<<endl;        
   }
   //while(1);      
   return 0;    
 }

C++: #include <iostream>
#include <math.h>
using namespace std;

int n;

void solve()
{
	double nx,ny,nr,mx,my,mr,pdist;


	cin >> nx >> ny >> nr >> mx >> my >> mr;
	pdist = sqrt(pow((nx-mx), 2.0) + pow((ny-my),2.0));

	if(pdist - nr + mr < 0.0){
		cout << 2 << endl;
	}
	else if((pdist - mr + nr < 0.0)){
		cout << -2 << endl;
	}
	else if(pdist - mr - nr > 0.0){
		cout << 0 << endl;
	}
	else {
		cout << 1 << endl;
	}
}

int main(void)
{
	cin >> n;
	while(--n, n>=0){
		solve();
	}
	return 0;
}

C++: #include <iostream>
#include <vector>
#include <cmath>

inline double distance(double xa, double ya, double xb, double yb){
	return std::sqrt(pow(xa - xb, 2) + pow(ya - yb, 2));
}

int judge(std::vector<double> ve){
	double center_dis = distance(ve[0], ve[1], ve[3], ve[4]);
	if(center_dis > ve[2] + ve[5]){
		return 0;	
	}else if(ve[2] >= center_dis + ve[5]){
		return 2;
	}else if(ve[5] >= center_dis + ve[2]){
		return -2;
	}else{
		return 1;
	}
}

int main(void){
	int num;
	std::vector<double> ve(6);

	std::cin >> num;

	for(int i = 0; i < num; ++i){
		std::cin >> ve[0] >> ve[1] >> ve[2] >> ve[3] >> ve[4] >> ve[5];
		
		std::cout << judge(ve) << std::endl;
	}
	return 0;
}