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
//------------------------------------------
#include <vector>
#include <list>
#include <map>
#include <set>
#include <deque>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <queue>
#include <iterator>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>

using namespace std;

//conversion
//------------------------------------------
inline int toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

//math
//-------------------------------------------
template<class T> inline T sqr(T x) {return x*x;}

//typedef
//------------------------------------------
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;
typedef unsigned long long ULL;

//container util
//------------------------------------------
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())

//repetition
//------------------------------------------
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

//constant
//--------------------------------------------
const double EPS = 1e-10;
const double PI  = acos(-1.0);

//clear memory
#define CLR(a) memset((a), 0 ,sizeof(a))

//debug
#define dump(x)  cerr << #x << " = " << (x) << endl;
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;

int gcd(int a, int b){
   int tmp;
   while(a%b==0){
      tmp=a%b;
      a=b;
      b=tmp;
   }
}

int lcm(int a,int b){
   return a*b/gcd(a,b);
}

bool prime_number(int n){
   if(n < 2){
      return false;
   }
   else if(n == 2){
      return true;
   }
   if(n % 2 == 0){
      return false;
   }
   for(int i=3;i<=n/i;i+=2){
      if(n % i == 0) return false;
      return true;
   }
}

int main(){
   int n;
   double x[2],y[2],r[2];
   cin>>n;
   REP(i,n){
      REP(j,2) cin >> x[j] >> y[j] >> r[j];
      if(sqrt(pow(x[1]-x[0],2)+pow(y[1]-y[0],2))>r[1]+r[0])
         cout << "0" << endl;
      else if(sqrt(pow(x[1]-x[0],2)+pow(y[1]-y[0],2))+r[1]<r[0])
         cout << "2" << endl;
      else if(sqrt(pow(x[1]-x[0],2)+pow(y[1]-y[0],2))+r[0]<r[1])
         cout << "-2" << endl;
      else cout << "1" << endl;
   }
}

C++: //SKDLKASDL+KASL+DKSAL+DK+LKASD
#include<stdio.h>
#include <algorithm>
#include <cassert>
#include <cctype>
#include <climits>
#include <cmath>
#include <complex>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <ctime>
#include <iostream>
#include <iterator>
#include <list>
#include <map>     
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <iomanip>
#include <stack>
#include <string>
#include <vector>
using namespace std;
#define ll long long
#define ld long double
#define roop(a,t) for(int a=0;a<t;a++) 
int main()
{
	cin.tie(0);
	ios::sync_with_stdio(false);
	ld x[2], y[2], r[2];
	ll n;
	cin >> n;
	roop(i, n) {
		roop(lp, 2) {
			cin >> x[lp] >> y[lp] >> r[lp];
		}
		ld ab = sqrt((x[0] - x[1])*(x[0] - x[1]) + (y[0] - y[1])*(y[0] - y[1]));
		if (r[0] + r[1] < ab) { cout << 0 << endl; continue; }
		else if (r[0] + r[1] == ab) { cout << 1 << endl; continue; }
		else {
			if (r[0] > r[1]) {
				if (r[0] > r[1] + ab) { cout << 2 << endl; continue; }
			}
			else {
				if (r[1] > r[0] + ab) { cout << 2 << endl; continue; }
			}
		}cout << 1 << endl;

	}
	return 0;
}

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


using namespace std;

int main(){
  int datasets = 0;
  cin >> datasets;

  for(int i=0;i<datasets;i++){
    double xa,ya,ra,xb,yb,rb;
    cin >> xa >> ya >> ra >> xb >> yb >> rb;

    //dis
    double dis = sqrt(pow(xa-xb, 2) + pow(ya-yb,2));
    
    if(ra+rb < dis){
      cout << "0" << endl;
      continue;
    }

    if(ra-rb > dis){
      cout << "2" << endl;
      continue;
    }

    if(rb-ra > dis){
      cout << "-2" << endl;
      continue;
    }

    if(ra+rb >= dis){
      cout << "1" << endl;
      continue;
    }
  }
}