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 <cstdio>
#include <complex>
#include <vector>
#include <cmath>

using namespace std;

#define REP(i, n) for(int i = 0;i < n;i++)
#define REPR(i, n) for(int i = n;i >= 0;i--)
#define FOR(i, m, n) for(int i = m;i < n;i++)

typedef complex<double> P;
typedef vector<P> VP;
const double EPF = 1e-2;

#define X real()
#define Y imag()
#define EQ(x,y) (abs(x-y) < EPF)
#define LE(x,y) (x < y + EPF)
#define GE(x,y) (x + EPF > y)

double dot(P a, P b) {
  return (conj(a)*b).X;
}
double cross(P a, P b) {
  return (conj(a)*b).Y;
}
int isparallel(P a, P b, P c, P d) {//ab,cd
  return EQ(cross(a-b, c-d),0);
}
double distPP(P a, P b) {
  return sqrt(dot(a-b,a-b));
}
int relationCC(P c1, double r1, P c2, double r2) {//0..not overlap, 1..intersect, 2..2isin1, -2..1isin2
  double d2 = dot(c1-c2,c1-c2);
  double prr = (r1+r2)*(r1+r2);
  double mrr = (r1-r2)*(r1-r2);
  if(GE(d2 ,prr)) return 0;
  else if(GE(mrr, d2)) {
    if(r1 > r2) return 2;
    else return -2;
  }
  else return 1;
}
P intersection(P a, P b, P c, P d) {//ac , bd
  double d1 = cross(d-b,b-a);
  double d2 = cross(d-b,c-a);
  if(EQ(d1,0) & EQ(d2,0)) return a;
  if(EQ(d2,0)) return a;
  return a + (c-a)*d1/d2;
}
P normal_vector(P a) {
  P b(-a.Y, a.X);
  return b;
}
P polar(double r, double theta) {
  P a(r*cos(theta),r*sin(theta));
  return a;
}


int main() {
  int n;
  scanf("%d",&n);
  REP(i,n) {
    double x,y,r1,r2;
    scanf("%lf %lf %lf", &x, &y, &r1);
    P a(x,y);
    scanf("%lf %lf %lf", &x, &y, &r2);
    P b(x,y);
    printf("%d\n", relationCC(a,r1,b,r2));
  }
  return 0;
}

C++: #include <iostream>
#include <algorithm>
#include <cmath>
#define EPS 0.000000001
using namespace std;

double X[2][60],Y[2][60],R[2][60];
int res[60];
int main(){
	int N;
	cin>>N;
	for(int i=1;i<=N;i++){
		for(int j=0;j<2;j++){
			cin>>X[j][i]>>Y[j][i]>>R[j][i];
		}
	}

	double re;
	for(int i=1;i<=N;i++){
		re=pow(X[0][i]-X[1][i],2)+pow(Y[0][i]-Y[1][i],2);
		if(re>=pow(R[0][i]+R[1][i],2)){
			res[i]=0;
		}
		else if(re>pow(R[0][i]-R[1][i],2)){
			res[i]=1;
		}
		else if(R[0][i]>R[1][i]){
			res[i]=2;
		}
		else res[i]=-2;
	}
	for(int i=1;i<=N;i++){
		cout<<res[i]<<endl;
	}
	return 0;
}

C++: #include <iostream>

using std::cin;

struct Circle {
    double x;
    double y;
    double r;
};

double pow2(double x);

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

    while (data_num--) {
        Circle a, b;
        cin >> a.x >> a.y >> a.r >> b.x >> b.y >> b.r;

        double dist = pow2(a.x - b.x) + pow2(a.y - b.y);

        int ans;
        if (dist > pow2(a.r + b.r)) {
            ans = 0;
        } else if (dist >= pow2(a.r - b.r)) {
            ans = 1;
        } else {
            ans = (a.r > b.r)? 2: (-2);
        }

        std::cout << ans << std::endl;
    }

    return 0;
}

double pow2(double x)
{
    return (x * x);
}

C++: #include <iostream>
#include <array>
#include <math.h>

int main(){

	std::array<double, 3> a; //0:xa 1:ya 2:ra
	std::array<double, 3> b;

	int N;
	std::cin >> N;

	for(int i = 0; i < N; ++i){
		
		for(int j = 0; j < 3; ++j)
			std::cin >> a[j];

		for(int j = 0; j < 3; ++j)
			std::cin >> b[j];

		double ab = hypot( (a[0] - b[0]) , (a[1] - b[1]) ); //distance a,b

		if( ab > (a[2] + b[2]) ) std::cout << 0 << std::endl;
		
		else if ( a[2] > ab + b[2] ) std::cout << 2 << std::endl;

		else if ( b[2] > ab + a[2] ) std::cout << -2 << std::endl;

		else std::cout << 1 << std::endl;

	}
	return 0;
}

C++: #include<bits/stdc++.h>
#include<vector>
#include<list>
#include<stack>
#include<queue>
#include<algorithm>
using namespace std;

int main(){
    int mod=1000000007;
    int n;
    int ans;
    double xa,ya,ra,xb,yb,rb;
    scanf("%d",&n);
    for (int i=0;i<n;i++) {
        scanf("%lf %lf %lf %lf %lf %lf",&xa,&ya,&ra,&xb,&yb,&rb);
        double tmp=sqrt((xa-xb)*(xa-xb)+(ya-yb)*(ya-yb));
        if ((tmp+rb)<ra) {
            printf("2\n");
        } else if ((tmp+ra)<rb) {
            printf("-2\n");
        } else if ((tmp)>(ra+rb)) {
            printf("0\n");
        } else {
            printf("1\n");
        }
    }
    return 0;
}

C++: #include<iostream>
#include<complex>
#include<cmath>
#include<map>
#define fs first
#define sc second
#define EPS (1e-6)
using namespace std;


typedef complex<double> P;
typedef pair<P,double> C;

int cpr(C a,C b){
  double d = abs(a.fs-b.fs);
  if(a.sc+b.sc + EPS < d)return -1;      //no intersection (outside)
  if(b.sc<a.sc && d + EPS < a.sc-b.sc)return 1;       //no intersection (inside,B in A)
  if(a.sc<b.sc && d + EPS < b.sc-a.sc)return 2;       //no intersection (inside,A in B)
  if(abs(a.sc+b.sc - d) < EPS)return -3; //one cross point (outside)
  if(abs(b.sc+d - a.sc) < EPS)return 3;  //one cross point (inside,B in A)
  if(abs(a.sc+d - b.sc) < EPS)return 4;  //one cross point (inside,A in B)
  return 0;                              //two cross point
}


int main(){
  double ax,ay,ar,bx,by,br;

  int n;
  cin >> n;
  for(int i=0;i<n;i++){
    cin>> ax >> ay >> ar >> bx >> by >> br;
    C a = C(P(ax,ay),ar), b = C(P(bx,by),br);
    int v = cpr(a,b);
    if(v==-1)cout <<  0 << endl;
    else if(v==1)cout << 2 << endl;
    else if(v==2)cout << -2 << endl;
    else cout << 1 << endl;
  }
}

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

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

    for(int i=0; i<n; i++){

        double xa, ya, ra, xb, yb, rb;
        cin >> xa >> ya >> ra >> xb >> yb >> rb;

        double d; // 中心間距離
        d = sqrt((xa-xb)*(xa-xb)+(ya-yb)*(ya-yb));

        if( d > ra + rb ) cout << "0\n";
        else if( ra - d > rb ) cout << "2\n";
        else if( rb - d > ra )cout << "-2\n";
        else cout << "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(r[0]+d < r[1]) cout << -2 << endl;
	else if(r[1]+d < r[0]) cout << 2 << endl;
	else cout << 1 << endl;
	}
	return 0;
}

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

using namespace std;

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

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