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 <cmath>
#include <iostream>
using namespace std;
int main()
{
    int n; cin >> n;
    while (n--) {
        double xa, ya, ra, xb, yb, rb;
        cin >> xa >> ya >> ra >> xb >> yb >> rb;
        double d = hypot(xa-xb, yb-yb);
        int res = 1;
        if (ra > rb) {
            if (d <= ra - rb) res = 2;
            else if (d > ra + rb) res = 0;
        }
        else {
            if (d <= rb - ra) res = -2;
            else if (d > ra + rb) res = 0;
        }
        cout << res << endl;
    }
    return 0;
}

C++: #include <stdio.h>
#include <math.h>

int main()
{
	int n, t;
	double x1, y1, r1, x2, y2, r2;
	double d;

	scanf("%d", &n);

	for (int i = 0; i < n; i++) {
		scanf("%lf %lf %lf %lf %lf %lf", &x1, &y1, &r1, &x2, &y2, &r2);

		d = (x2-x1)*(x2-x1) + (y2-y1)*(y2-y1);

		if (d > (r1 + r2)*(r1 + r2)) t = 0;
		else if (d < (r2-r1)*(r2-r1)){
			if (r2 < r1) t = 2;
			else if (r2 > r1) t = -2;
		}else t = 1;

		printf("%d\n", t);
	}

	return 0;
}

C++: // AOJ 0023
#include<iostream>
#define REP(i,n) for(int i=0;i<(int)(n);i++)
using namespace std;

const long double EPS = 1e-10;

long double sq(long double x) {
  return x * x;
}

long double abs(long double x) {
  return (x > 0 ? x : -x);
}

bool eq(long double x, long double y) {
  return abs(x - y) < EPS;
}

long double dist(int xa, int ya, int xb, int yb) {
  return sq(xa - xb) + sq(ya - yb);
}

int main() {
  int n;
  cin >> n;
  REP(i, n) {
    long double xa, ya, ra, xb, yb, rb;
    cin >> xa >> ya >> ra >> xb >> yb >> rb;

    long double d = dist(xa, ya, xb, yb);
    
    if (sq(ra) > d + EPS) {
      cout << 2 << endl;
    } else if (sq(rb) > d + EPS) {
      cout << -2 << endl;
    } else if (d > sq(ra + rb) + EPS) {
      cout << 0 << endl;
    } else {
      cout << 1 << endl;
    }
  }
}

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

int main() {
    int n;
    cin >> n;
    while (n--) {
        double xa, ya, ra, xb, yb, rb;
        cin >> xa >> ya >> ra >> xb >> yb >> rb;
        double dist2 = pow(xa - xb, 2) + pow(ya - yb, 2),
            radiusSum2 = pow(ra + rb, 2);
        int res;
        if (dist2 > radiusSum2) {
            res = 0;
        } else if (dist2 == radiusSum2) {
            res = 1;
        } else if (ra < rb) {
            res = -2;
        } else {
            res = 2;
        }
        cout << res << endl;
    }
}

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

int main() {
  int n;
  double xa,ya,ra;
  double xb,yb,rb;
  
  cin>>n;

  for(int i=0; i<n; i++) {
    cin>>xa>>ya>>ra>>xb>>yb>>rb;
    
    double segAB = sqrt( (xb-xa)*(xb-xa) + (yb-ya)*(yb-ya) );
    int res;
    if(ra+rb < segAB) res = 0;
    if(abs(ra-rb)<segAB && segAB<ra+rb) res = 1;
    if(segAB <= rb-ra) res = -2;
    if(segAB <= ra-rb) res = 2;
    
    cout << res << endl;
  }
    
  return 0;
}

C++: // AOJ 0023
#include<iostream>
#define REP(i,n) for(int i=0;i<(int)(n);i++)
using namespace std;

const long double EPS = 1e-6;

long double sq(long double x) {
  return x * x;
}

long double abs(long double x) {
  return (x > 0 ? x : -x);
}

bool eq(long double x, long double y) {
  return abs(x - y) < EPS;
}

long double dist(long double xa, long double ya, long double xb, long double yb) {
  return sq(xa - xb) + sq(ya - yb);
}

int main() {
  int n;
  cin >> n;
  REP(i, n) {
    long double xa, ya, ra, xb, yb, rb;
    cin >> xa >> ya >> ra >> xb >> yb >> rb;

    long double d = dist(xa, ya, xb, yb);
//    cout << d << endl;
    
    if (sq(ra) > d + EPS) {
      cout << 2 << endl;
    } else if (sq(rb) > d + EPS) {
      cout << -2 << endl;
    } else if (d > sq(ra + rb) + EPS) {
      cout << 0 << endl;
    } else {
      cout << 1 << endl;
    }
  }
}

C++: // AOJ 0023
#include<iostream>
#define REP(i,n) for(int i=0;i<(int)(n);i++)
using namespace std;

const double EPS = 1e-8;

double sq(double x) {
  return x * x;
}

double abs(double x) {
  return (x > 0 ? x : -x);
}

bool eq(double x, double y) {
  return abs(x - y) < EPS;
}

double dist(int xa, int ya, int xb, int yb) {
  return sq(xa - xb) + sq(ya - yb);
}

int main() {
  int n;
  cin >> n;
  REP(i, n) {
    double xa, ya, ra, xb, yb, rb;
    cin >> xa >> ya >> ra >> xb >> yb >> rb;

    double d = dist(xa, ya, xb, yb);
    
    if (d < sq(ra)) {
      cout << 2 << endl;
    } else if (d < sq(rb)) {
      cout << -2 << endl;
    } else if (eq(d, ra) or eq(d, rb)) {
      cout << 1 << endl;
    } else if (d < sq(ra + rb)) {
      cout << 1 << endl;
    } else {
      cout << 0 << endl;
    }
  }
}

C++: #include<iostream>
#include<cmath>
int main()
{
	int n;
	std::cin >> n;
	for (int i = 0; i < n; i++)
	{
		long double xa, ya, ra, xb, yb, rb;
		std::cin >> xa >> ya >> ra >> xb >> yb >> rb;
		long double d = hypot(xa - xb, ya - yb);
		if (d < abs(ra - rb))
		{
			std::cout << 2 * (ra < rb ? -1 : 1) << std::endl;
		}
		else if (d <= ra + rb)
		{
			std::cout << 1 << std::endl;
		}
		else
		{
			std::cout << 0 << std::endl;
		}
	}
	return 0;
}

C++: #include<iostream>
#include<vector>
#include<complex>
using namespace std;

typedef pair<double,double>vec;

double norm(vec v1,vec v2){
    return sqrt((v1.first-v2.first)*(v1.first-v2.first)+(v1.second-v2.second)*(v1.second-v2.second));
}
int main()
{
    int n;
    cin>>n;
    while(n--){
        double x1,y1,r1,x2,y2,r2;
        cin>>x1>>y1>>r1>>x2>>y2>>r2;
        vec v1=make_pair(x1,y1);
        vec v2=make_pair(x2,y2);
        double dis=norm(v1,v2);
        if(dis-(r1+r2)>1e-10)
            cout<<0<<endl;
        else if(abs(dis-abs(r1-r2))>1e-10&&abs(dis-(r1+r2))<1e-10){
            cout<<1<<endl;
        }
        else if(abs(r1-r2)>1e-10){
            cout<<2<<endl;
        }
        else cout<<-2<<endl;
    }
    return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<algorithm>
#include<vector>
#include<string>
#include<map>
#include<set>
#include<unordered_map>
#include<unordered_set>
#include<list>
#include<queue>
#include<stack>
#include<deque>
using namespace std;

int main() {
	int a; cin >> a;
	for (int b = 0; b < a; b++) {
		double x1, y1, r1, x2, y2, r2;
		cin >> x1 >> y1 >> r1 >> x2 >> y2 >> r2;
		double s = sqrt((x1-x2)*(x1-x2)+(y1-y2)*(y1-y2));
		if (s+r1 - r2 <= 0.00000001) {
			puts("-2");
		}
		else if (r2 + s - r1 <= 0.00000001) {
			puts("2");
		}
		else if (s - r2 - r1 > 0.00000001) {
			puts("0");
		}
		else puts("1");
	}
}

C++: #include<iostream>
#include<cmath>
int main()
{
	int n;
	std::cin >> n;
	for (int i = 0; i < n; i++)
	{
		double xa, ya, ra, xb, yb, rb;
		std::cin >> xa >> ya >> ra >> xb >> yb >> rb;
		double d = hypot(xa - xb, ya - yb);
		if (d < abs(ra - rb))
		{
			std::cout << 2 * (ra < rb ? -1 : 1) << std::endl;
		}
		else if (d <= ra + rb)
		{
			std::cout << 1 << std::endl;
		}
		else
		{
			std::cout << 0 << std::endl;
		}
	}
	return 0;
}