判断线段是否在园内

给出圆心坐标和半径 还有线段的两个端点 判断线段是全在圆内还是部分在圆内 或是 全在圆外

#include<iostream>
#include<stdio.h>
#include<math.h>
using namespace std;
struct point{double x;double y;};

double length(point a,point b)
{
    return sqrt((a.x-b.x)*(a.x-b.x)+(a.y-b.y)*(a.y-b.y));    

}

double dot(point a,point b)
{
    return a.x*b.x+a.y*b.y;
}

double cross(point a,point b)
{
    return a.x*b.y-a.y*b.x;
}

int dcmp(double x)
{
    if(fabs(x)<0.000001)
        return 0;
    if(x<0)
        return -1;
    return 1;
}



double dis(point p,point a,point b)
{
    
    point v1,v2,v3;
    v1.x=b.x-a.x; v1.y=b.y-a.y;
    v2.x=p.x-a.x; v2.y=p.y-a.y;
    v3.x=p.x-b.x; v3.y=p.y-b.y;
    if(dcmp(dot(v1,v2))<0)  return length(p,a);
    else if(dcmp(dot(v1,v3))>0) return length(p,b);
    return fabs(cross(v1,v2))/length(b,a);

}


int main()
{
    int i,j,n,m,t;
    point c,a,b;
    double r,l1,l2,l3;
    scanf("%d",&n);
    while(n--)
    {
        scanf("%lf%lf%lf",&c.x,&c.y,&r);
        scanf("%lf%lf%lf%lf",&a.x,&a.y,&b.x,&b.y);
        l1=length(a,c);
        l2=length(b,c);
        l3=dis(c,a,b);
    //    printf("dis  %lf  %lf  %lf\n",l1,l2,l3);
        if(l1<=r&&l2<=r)
            printf("ALL IN\n");
    
            
        else if (l1>=r&&l2>=r&&l3>=r)
            printf("ALL OUT\n");
        else
            printf("PART IN\n");
    }
    return 0;
}