uva 10697

超煩的控制精確值跟誤差值

//============================================================================
// Name        : Firemen barracks.cpp
// Date : 2013/5/9 下午1:40:03
// Author : GCA
//============================================================================
#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <algorithm>
#include <cmath>
#include <climits>
#include <vector>
#include <set>
#include <map>
#include <queue>
#include <cctype>
#include <utility>
using namespace std;
#ifdef ONLINE_JUDGE
#define ll "%lld"
#else
#define ll "%I64d"
#endif
typedef unsigned int uint;
typedef long long int Int;
#define Set(a,s) memset(a,s,sizeof(a))
#define Write(w) freopen(w,"w",stdout)
#define Read(r) freopen(r,"r",stdin)
#define Pln() printf("\n")
#define I_de(x,n)for(int i=0;i<n;i++)printf("%d ",x[i]);Pln()
#define De(x)printf(#x"%d\n",x)
#define For(i,x)for(int i=0;i<x;i++)
#define CON(x,y) x##y
#define Pmz(dp,nx,ny)for(int hty=0;hty<ny;hty++){for(int htx=0;htx<nx;htx++){\
    printf("%d ",dp[htx][hty]);}Pln();}
#define M 10011
#define PII pair<int,int>
#define PB push_back
#define oo INT_MAX
#define Set_oo 0x3f
#define Is_debug true
#define debug(...) if(Is_debug)printf("DEBUG: "),printf(__VA_ARGS__)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin();it!=(c).end();it++)
#define eps 1e-6
#define deps 1e-1
bool xdy(double x,double y){return x>y+eps;}
bool xddy(double x,double y){return x>y-eps;}
bool xcy(double x,double y){return x<y-eps;}
bool xcdy(double x,double y){return x<y+eps;}
bool xdddy(double x,double y){return fabs(x-y)<eps;}
bool txdddy(double x,double y){return fabs(x-y)<deps;}
int min3(int x,int y,int z){
    int tmp=min(x,y);
    return min(tmp,z);
}
int max3(int x,int y,int z){
    int tmp=max(x,y);
    return max(tmp,z);
}
struct point{
    double x,y;
}p[3];
inline void swap(double &a,double &b){
    double tmp=a;a=b;b=tmp;
}
void solve(){
    double a1,b1,c1,a2,b2,c2;
    double x1=p[0].x,y1=p[0].y;
    double x2=p[1].x,y2=p[1].y;
    double x3=p[2].x,y3=p[2].y;
    double ansx,ansy;
    a1=2*(x2-x1);
    b1=2*(y2-y1);
    c1=x1*x1-x2*x2+y1*y1-y2*y2;
    a2=2*(x3-x1);
    b2=2*(y3-y1);
    c2=x1*x1-x3*x3+y1*y1-y3*y3;
    if(((x1==x2&&x2==x3&&y1==y2&&y2==y3))||(x1==x2&&y1==y2)||(x1==x3&&y1==y3)||(x2==x3&&y2==y3)){
        printf("There is an infinity of possible locations.\n");
        return;
    }


    if(xdddy((x1-x2)*(y1-y3),(x1-x3)*(y1-y2))){
        printf("There is no possible location.\n");
        return;
    }
    if(xdddy(a1,0)){
        swap(a1,a2);
        swap(b1,b2);
        swap(c1,c2);
    }
    double ob=b1,oc=c1,oa=a1;
    b1*=(a2/a1);
    c1*=(a2/a1);
    ansy=-(c1-c2)/(b1-b2);
    ansx=-(ansy*ob+oc)/oa;
    if((ansx-0.05)<eps&&(ansx+0.05)>eps){
        ansx=0.0;
    }else{
        if(ansx<eps)ansx-=eps;
    }
    if((ansy-0.05)<eps&&(ansy+0.05)>eps){
        ansy=0.0;
    }else{
        if(ansy<eps)ansy-=eps;
    }
    printf("The equidistant location is (%.1lf, %.1lf).\n",ansx,ansy);
}
int main() {
    ios_base::sync_with_stdio(0);
    int test;
    scanf("%d",&test);
    while(test--){
        for(int i=0;i<3;i++){
            scanf("%lf%lf",&p[i].x,&p[i].y);
        }
        solve();
    }

















}