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 <iostream>
#include <iomanip>
#include <sstream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
#include <cfloat>
#include <vector>
#include <string>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <algorithm>
#include <functional>
#include <utility>
#include <numeric>
#include <iterator>

using namespace std;

typedef long long LL;
typedef unsigned long long ULL;
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int,int> PII;
typedef istringstream ISS;
typedef ostringstream OSS;

#define REP( i, m, n ) for ( int i = (int)( m ); i < (int)( n ); ++i )
#define FOR( v, c ) for ( auto &v : c )

#define EACH( it, c ) for ( auto it = c.begin(); it != c.end(); ++it )
#define ALL( c ) (c).begin(), (c).end()
#define DRANGE( c, p ) (c).begin(), (c).begin() + p, (c).end()

#define PB( n ) push_back( n )
#define MP( a, b ) make_pair( ( a ), ( b ) )
#define EXIST( c, e ) ( (c).find( e ) != (c).end() )

#define fst first
#define snd second

#define DUMP( x ) cerr << #x << " = " << ( x ) << endl
#define DEBUG( x ) cerr << __FILE__ << ":" << __LINE__ << ": " << #x << " = " << ( x ) << endl

const double EPS = 1e-8;

struct Point
{
	double x, y;

	Point() : x( 0 ), y( 0 ) {}
	Point( const double x, const double y ) : x( x ), y( y ) {}
	Point( const Point &a ) : x( a.x ), y( a.y ) {}
	
	const Point operator + ( const Point &a ) const
	{
		return Point( x + a.x, y + a.y );
	}

	Point& operator += ( const Point &a ) 
	{
		x += a.x;
		y += a.y;

		return *this;
	}

	const Point operator - ( const Point &a ) const
	{
		return Point( x + ( -a.x ), y + ( -a.y ) );
	}

	Point& operator -= ( const Point &a )
	{
		x -= a.x;
		y -= a.y;

		return *this;
	}

	const Point operator * ( const double a ) const
	{
		return Point( x * a, y * a );
	}

	Point& operator *= ( const double a )
	{
		x *= a;
		y *= a;

		return *this;
	}

	const Point operator / ( const double a ) const
	{
		return Point( x / a, y / a );
	}

	Point& operator /= ( const double a )
	{
		x /= a;
		y /= a;

		return *this;
	}

	bool operator < ( const Point &a ) const
	{
		return x == a.x ? y < a.y : x < a.x;
	}

	double abs() const
	{
		return sqrt( pow( x, 2. ) + pow( y, 2. ) );
	}

	const Point unitVector() const
	{
		return *this / abs();
	}

	const Point normalVector1() const
	{
		return Point( y, -x );
	}

	const Point normalVector2() const
	{
		return Point( -y, x );
	}
};

// 二点間の距離
double distance( const Point &a, const Point &b )
{
	return ( a - b ).abs();
}

// 二つの円 ( p1, r1 ) と ( p2, r2 ) の位置関係
// 交差しない : 0
// 交わる：1
// 1 が 2 を含む : 2
// 2 が 1 を含む : 3
// その他 4
int circles_relation( const Point &p1, const double r1, const Point &p2, const double r2 )
{
	const double dist = distance( p1, p2 );
	if ( r1 + r2 + EPS < dist )
	{
		return 0;
	}
	else if ( abs( r1 - r2 ) <= dist + EPS && dist <= r1 + r2 + EPS )
	{
		return 1;
	}
	else if ( dist <= abs( r1 - r2 ) + EPS )
	{
		return r1 < r2 + EPS ? 3 : 2;
	}
	else
	{
		return 4;
	}
}

int main()
{
	cin.tie( 0 );
	ios::sync_with_stdio( false );
	
	int n;
	cin >> n;

	REP( casenum, 0, n )
	{
		double xa, ya, ra, xb, yb, rb;
		cin >> xa >> ya >> ra >> xb >> yb >> rb;
		
		int res = circles_relation( Point( xa, ya ), ra, Point( xb, yb ), rb );
		
		switch ( res )
		{
			case 0:
				cout << 0 << endl;
				break;
			case 1:
				cout << 1 << endl;
				break;
			case 2:
				cout << 2 << endl;
				break;
			case 3:
				cout << 3 << endl;
				break;
		}
	}

	return 0;
}

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

int main() {
    int n;
    cin >> n;
    double xa, ya, ra, xb, yb, rb;
    while (n--) {
        cin >> xa >> ya >> ra >> xb >> yb >> rb;
        double d = sqrt((xb - xa) * (xb - xa) + (yb - ya) * (yb - ya));
        if (ra + rb <= d + 1e-9) {
            cout << 0 << endl;
        } else if (d + ra < rb + 1e-9) {
            cout << -2 << endl;
        } else if (d + rb < ra + 1e-9) {
            cout << 2 << endl;
        } else {
            cout << 1 << endl;
        }
    }
    return 0;
}

C++: #include<iostream>
#include<complex>
using namespace std;
typedef complex<double> P;

#define EPS (1e-10)
#define EQ(a,b) (abs((a)-(b)) < EPS)
#define EQV(a,b) ( EQ((a).real(), (b).real()) && EQ((a).imag(), (b).imag()) )

int main(){
	P x,y;
	double r1,r2,dis;
	int n;
	cin>>n;
	while(n--){
		cin>>x.real()>>x.imag()>>r1>>y.real()>>y.imag()>>r2;
		dis=abs(x-y);
		if(dis>r1+r2+EPS){
			cout<<"0"<<endl;
		}else if(dis>abs(r1-r2)-EPS){
			cout<<"1"<<endl;
		}else{
			if(r1>r2)
				cout<<"2"<<endl;
			else
				cout<<"-2"<<endl;
		}
	}
	return 0;
}

C++: #include <iostream>
#include <string>
#include <cmath>
#include <list>
#include <map>
#include <vector>

using namespace std;

int checkIntersection(double xa,double ya,double ra,double xb,double yb, double rb){
    double d = (xa-xb)*(xa-xb) + (ya-yb)*(ya-yb);
    double sr = (ra+rb)*(ra+rb);
    double dr = (ra-rb)*(ra-rb);
    
    if (d > sr){
        return 0;
    }else if(d<sr && d<d){
        return 1;
    }else if(dr>d){
        return (ra>rb)?2:-2;
    }else return 1;
    
    
    
}

int main (int argc, char const* argv[]){
    double xa, ya,ra, xb,yb,rb;
    int i, n, result;
    
    cin >> n;
    while(cin >> xa>> ya>>ra>> xb>> yb>> rb){
        result = checkIntersection(xa, ya,ra, xb,yb,rb);
        
        cout << result << endl;
    }
    
    
    return 0;
}

C++: // clear time: 00:20
#include <iostream>
#include <string>
#include <vector>
#include <cmath>

#define TIMES(i) while(i--)
#define REP(i, n) for ( int i = 0; i < n; i++ )

using namespace std;

int main() {
    int n;
    cin >> n;

    TIMES(n) {
        // 入力
        double ax, ay, ar, bx, by, br;
        cin >> ax >> ay >> ar >> bx >> by >> br;

        // 距離を求める
        double dis_x = abs(ax-bx),
            dis_y = abs(ay-by),
            dist = sqrt(dis_x * dis_x + dis_y * dis_y);

        // cout << dis_x << " " << dis_y << " " << dist << endl;

        // 離れている
        if ( dist > ar + br ) {
            cout << 0;

        // aが内包されている
        } else if ( dist + ar < br ) {
            cout << -2;

        // bが内包されている
        } else if ( dist + br < ar ) {
            cout << 2;

        // 交わっている
        } else {
            cout << 1;
        }
        cout << endl;
    }

    return 0;
}