Go: package main

import (
        "fmt"
        "math"
)

func main() {
        var n int
        fmt.Scanf("%d", &n)
        for i := 0; i < n; i++ {
                var ax, ay, ar, bx, by, br float64
                fmt.Scanf("%f %f %f %f %f %f", &ax, &ay, &ar, &bx, &by, &br)

                d := math.Sqrt((bx-ax)*(bx-ax) + (by-ay)*(by-ay))
                if d <= ar + br {
                        if ar > br {
                                if ar > br + d {
                                        fmt.Println("2")
                                } else {
                                        fmt.Println("1")
                                }
                        } else {
                                if br > ar + d {
                                        fmt.Println("-2")
                                } else {
                                        fmt.Println("1")
                                }
                        }
                } else {
                        fmt.Println(0)
                }
        }
}

C++: #include <bits/stdc++.h>
using namespace std;

double eps = 1e-10;

class Point {
public:
	double x, y;
	
	Point(double x = 0, double y = 0) : x(x), y(y) {}
	
	Point operator + (const Point& p) {
		return Point(x + p.x, y + p.y);
	}
	Point operator - (const Point& p) {
		return Point(x - p.x, y - p.y);
	}
	Point operator * (const double& a) {
		return Point(x * a, y * a);
	}
	Point operator / (const double& a) {
		return Point(x / a, y / a);
	}
	
	bool operator < (const Point& p) const {
		return x != p.x ? x < p.x : y < p.y;
	}
	bool operator == (const Point& p) const {
		return fabs(x - p.x) < eps && fabs(y - p.y) < eps;
	}
	
	double abs() {
		return sqrt(norm());
	}
	double norm() {
		return x * x + y * y;
	}
	
};

class Circle {
public:
	Point c;
	double r;
	Circle(Point c = Point(), double r = 0.0) : c(c), r(r) {}
};

int main() {
	int n;
	cin >> n;
	double x1, y1, r1, x2, y2, r2;
	for(int i = 0; i < n; ++i){
		cin >> x1 >> y1 >> r1 >> x2 >> y2 >> r2;
		Circle c1 = Circle(Point(x1, y1), r1);
		Circle c2 = Circle(Point(x2, y2), r2);
		double minr = min(c1.r, c2.r);
		double maxr = max(c1.r, c2.r);
		
		if(pow(c2.c.x - c1.c.x, 2.0) + pow(c2.c.y - c1.c.y, 2.0) + pow(minr, 2.0) < pow(maxr, 2.0)){
			if(c1.r > c2.r)
				cout << "2" << endl;
			else
				cout << "-2" << endl;
		}
		else if(pow(c2.c.x - c1.c.x, 2.0) + pow(c2.c.y - c1.c.y, 2.0) <= pow(c1.r + c2.r, 2.0)){
			cout << "1" << endl;
		}
		else{
			cout << "0" << endl;
		}
	}
	return 0;
}

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

using namespace std;

double X1,Y1,r1,X2,Y2,r2;

int main()
{
    int n; scanf( "%d\n", &n );
    while( n > 0 ){
        scanf("%lf %lf %lf %lf %lf %lf\n", &X1, &Y1, &r1, &X2, &Y2, &r2 );
        double dx = X2 - X1, dy = Y2 - Y1;
        double dis = sqrt( dx * dx + dy * dy );


        if( dis < r1 - r2 )
        {
            printf( "%d\n", 2 );
        }
        else if( dis < r2 - r1 )
        {
            printf( "%d\n", -2 );
        }
        else if( abs( r2 - r1 ) <= dis && dis <= r2 + r1 )
        {
            printf( "%d\n", 1 );
        }
        else
        {
            printf( "%d\n", 0 );
        }
        n--;
    }
    return 0;
}

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<stdio.h>
#include<math.h>

int main()
{
	int n,x;
	double xa,ya,ra,xb,yb,rb,d;

	scanf("%d",&n);
	for(x=0;x<n;x++)
	{
		scanf("%lf %lf %lf %lf %lf %lf",&xa,&ya,&ra,&xb,&yb,&rb);

		d=sqrt((xa-xb)*(xa-xb)+(ya-yb)*(ya-yb));

		if(ra+rb<d)
		{
			printf("0\n");
		}
		else if(ra<rb&&d<rb-ra)
		{
			printf("-2\n");
		}
		else if(rb<ra&&d<ra-rb)
		{
			printf("2\n");
		}
		else
		{
			printf("1\n");
		}
		return 0;
	}
}

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

int main() {
	int n; scanf("%d", &n);
	for(int i = 0; i < n; i++) {
		double xa,ya,ra,xb,yb,rb;
		scanf("%lf%lf%lf%lf%lf%lf", &xa,&ya,&ra,&xb,&yb,&rb);
		ra = fabs(ra);
		rb = fabs(rb);
		double xd = xa-xb;
		double yd = ya-yb;
		double rd = ra+rb;
		double rd2 = fabs(ra-rb);
		double sq_cdist = xd*xd+yd*yd;
		double sq_rdist = rd*rd;
		double sq_rdist2 = rd2*rd2;
		if(sq_cdist<sq_rdist2) {
			if(ra>rb) {
				printf("2\n");
			} else {
				printf("-2\n");
			}
		} else if(sq_cdist<=sq_rdist) {
			printf("1\n");
		} else {
			printf("0\n");
		}
	}
	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, a, n) for(int i = a; i < n; i++)
#define repb(i, a, b) for(int i = a; i >= b; i--)
#define all(a) a.begin(), a.end()
#define int long long
using namespace std;
typedef pair<int, int> P;

signed main(){
    int n;
    cin >> n;
    rep(i, 0, n){
        int ans;
        double x[2], y[2], r[2];
        rep(j, 0, 2) cin >> x[j] >> y[j] >> r[j];
        double d = sqrt(pow(x[0] - x[1], 2) + pow(y[0] - y[1], 2));
        if(r[0] + r[1] < d) ans = 0;
        else if(fabs(r[0] + r[1] - d) < 1e-10) ans = 1;
        else if(r[0] > d + r[1]) ans = 2;
        else if(r[1] > d + r[0]) ans = -2;
        cout << ans << endl;
    }
}

C++: #include <cmath>
#include <cstdio>
int n; long double xa, ya, ra, xb, yb, rb;
int main() {
	scanf("%d", &n);
	for(int i = 0; i < n; i++) {
		scanf("%Lf%Lf%Lf%Lf%Lf%Lf", &xa, &ya, &ra, &xb, &yb, &rb);
		long double dist = sqrtl((xa - xb) * (xa - xb) + (ya - yb) * (ya - yb));
		if(dist >= ra + rb - 1e-6) {
			printf("0\n");
		}
		else if(dist <= ra - rb + 1e-6) {
			printf("2\n");
		}
		else if(dist <= rb - ra + 1e-6) {
			printf("-2\n");
		}
		else  {
			printf("1\n");
		}
	}
	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<complex>
#define EPS 1e-10
using namespace std;

typedef complex<double>P;

int main(){
	int n;
	cin>>n;
	for(int i=0;i<n;i++){
		double ra,rb;
		P pa,pb;
		
		cin>>pa.real()>>pa.imag()>>ra;
		cin>>pb.real()>>pb.imag()>>rb;
		double d=abs(pa-pb);
		if(d+ra-rb<EPS)cout<<-2<<endl;
		else if(d+rb-ra<EPS)cout<<2<<endl;
		else if(d-ra-rb<EPS)cout<<1<<endl;
		else cout<<0<<endl;
	}
}