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 <iomanip>
#include <cassert>
#include <algorithm>
#include <functional>
#include <vector>
#include <string>
#include <cstring>
#include <stack>
#include <queue>
#include <map>
#include <bitset>
#include <sstream>
#include <istream>
#include <cmath>
#include <cstdio>

using namespace std;

#define vci vector<int>
#define vcs vector<string>
#define pb push_back
#define sz size()
#define mapci map<char, int>
#define mapsi map<string, int>
#define all(x) x.begin(), x.end()

#define for_(i, a, b) for (int i=(int)a; i<(int)b; i++)
#define for_d(i, a, b) for (int i=(int)a-1; i>=b; i--)
#define for_r(i, a, b, c) for (int i=(int)a; i<(int)b; i += c)
#define for_dr(i, a, b, c) for (int i=(int)a-1; i>=b; i -= c)
#define FOR(i,c) for(__typeof((c).begin())i=(c).begin();i!=(c).end();++i)

#define vcitr vector<int>::iterator
#define vcsitr vector<string>::iterator
#define mapcitr map<char, int>::iterator
#define mapsitr map<string, int>::iterator

typedef long long ll;

const int iINF = 2147483647;
const ll lINF = 9223372036854775807;

template <class T> inline void dbg(T t) { cout << t << endl; }

struct Point2D { 
	double x, y;
	Point2D (double a=0, double b=0) { x=a; y=b; }
};

typedef Point2D Vector2D;

double dist2D(const Point2D& a, const Point2D& b) { return sqrt( (a.x-b.x)*(a.x-b.x) + (a.y-b.y)*(a.y-b.y) ); }

Vector2D sub_vector2D(const Vector2D& a, const Vector2D& b) {
	Vector2D ret;
	ret.x = a.x - b.x; ret.y = a.y - b.y;
	return ret;
}

double cross_product(const Vector2D& a, const Vector2D& b) { return a.x*b.y - a.y*b.x; }

double inner_product(const Vector2D& a, const Vector2D& b) { return a.x*b.x + a.y*b.y; }

bool point_in_triangle_2D(const Point2D& a, const Point2D& b, const Point2D& c, const Point2D& p) {
	Vector2D ab = sub_vector2D(b, a); Vector2D bp = sub_vector2D(p, b);
	Vector2D bc = sub_vector2D(c, b); Vector2D cp = sub_vector2D(p, c);
	Vector2D ca = sub_vector2D(a, c); Vector2D ap = sub_vector2D(p, a);
	double c1 = cross_product(ab, bp), c2 = cross_product(bc, cp), c3 = cross_product(ca, ap);
	return ( (c1>0 && c2>0 && c3>0) || (c1<0 && c2<0 && c3<0) );
}

struct Circle {
	Point2D c; 
	double r;
	Circle (double a=0, double b=0, double rr=0) { c.x=a; c.y=b; r=rr; }
};

bool point_in_circle(const Point2D& p, const Circle& t) {
	double dist = dist2D(p, t.c);
	return (dist <= t.r);
}

bool circle_collision (const Circle& a, const Circle& b) {
	double len = dist2D(a.c, b.c);
	return (len <= a.r+b.r);
}

bool circle_in_circle(const Circle& a, const Circle& b) {	// a in b
	double len = dist2D(a.c, b.c);
	return (a.r+len <= b.r);
}

int main() {
	int n; cin >> n;
	Circle a, b;
	
	for_(i, 0, n) {
		cin >> a.c.x >> a.c.y >> a.r >> b.c.x >> b.c.y >> b.r;
		
		if (circle_in_circle(b, a)) cout << 2 << endl;
		else if (circle_in_circle(a, b)) cout << -2 << endl;
		else if (circle_collision(a, b)) cout << 1 << endl;
		else cout << 0 << endl;
	}
	
	return 0;
}

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

int main() {
	int n;
	double x_a, y_a, r_a, x_b, y_b, r_b;
	cin >> n;

	for (int i = 0; i < n; i++) {
		cin >> x_a >> y_a >> r_a >> x_b >> y_b >> r_b;
		double distance2 = (x_a - x_b)*(x_a - x_b) + (y_a - y_b)*(y_a - y_b);

		if (distance2 > (r_a + r_b)*(r_a + r_b)) {
			cout << 0 << endl;
		} else if (distance2 >= (r_a - r_b)* (r_a - r_b)){
			cout << 1 << endl;
		} else if(r_a > r_b){
			cout << 2 << endl;
		} else {
			cout << -2 << endl;
		}
	}


	return 0;
}

C++: #include<iostream>
#include<string>
#include<cstdio>
#include<algorithm>
#include<stack>
#include<queue>
#include<vector>
#include<cmath>
#include<utility>
#define ll long long int
#define ld long double
#define INF 1000000000
#define EPS 0.0000000001
#define rep(i,n) for(i=0;i<n;i++)
using namespace std;
typedef pair<int, int> P;

string str;

int main()
{
  ll n,i;
  ld xa,ya,ra,xb,yb,rb;
  ld dist;

  cin>>n;
  rep(i,n){

    cin>>xa>>ya>>ra>>xb>>yb>>rb;
    dist=sqrt( (xa-xb)*(xa-xb)+(ya-yb)*(ya-yb) );

    if(dist>ra+rb)
      cout<<"0"<<endl;
    else if(rb<dist || ra<dist || ra==rb)
      cout<<"1"<<endl;
    else if(rb<ra)
      cout<<"2"<<endl;
    else if(ra<rb)
      cout<<"-2"<<endl;
  }
}

C++: #include<iostream>
#include<cstdio>
#include<cmath>
using namespace std;
int main(){
    int n;
    cin>>n;
    for(int a=0;a<n;a++){
        double p,q,r,s,t,u;
        cin>>p>>q>>r>>s>>t>>u;
        double A,B,C;
        A=r;
        B=u;
        C=sqrt((p-s)*(p-s)+(q-t)*(q-t));
        if(B+C<A)cout<<"2";
        else if(A+C<B)cout<<"-2";
        else if(C>A+B)cout<<"0";
        else cout<<"1";
        cout<<endl;
         
    }
    return 0;
}

C++: #include <iostream>
#include <cmath>
#include <cstdio>
#include <complex>

using namespace std;

typedef complex<double> P;

int main(void){
  int n; cin >> n;
  while(n--){
    double ra, rb;
    P a,b;
    cin  >> a.real() >> a.imag() >> ra >> a.real() >> b.imag() >> rb;
    double d = abs(a-b);
    int ans;
    if(d > ra + rb) ans = 0;
    else if(d + ra >= rb) ans = 2;
    else if(d + rb >= ra) ans = -2;
    else ans= 1;
    cout << ans << endl;
  }
  return 0;
}

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

int main(int argc, char *argv[]) {
	int dataN;
	scanf("%d", &dataN);
	for (int i = 0; i < dataN; i++) {
		float ax, ay, ra, bx, by, rb;
		scanf("%f %f %f %f %f %f", &ax, &ay, &ra, &bx, &by, &rb);
		double d = (ax-bx)*(ax-bx) + (ay-by)*(ay-by);

		d = sqrt(d);

		if (ra > rb && ra > d + rb) {
		  cout<<2<<endl;
		} else if (rb > ra && rb > d + ra) {
		  cout<<-2<<endl;
		} else if (ra + rb < d) {
		  cout<<0<<endl;
		} else {
		  cout<<1<<endl;
		}
	}
	return 0;
}

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

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