c_cpp 第三题

Posted 2021-05-14

#include <bits/stdc++.h>
 
using namespace std;
 
class Point{
public:
    double x, y;
    Point(double a, double b): x(a), y(b) {}
    Point(const Point& p) {
        x = p.x;
        y = p.y;
    }
    void setx(int a) { x = a; }
    void sety(int b) { y = b; }
    double getx() { return x; }
    double gety() { return y; }
};
 
class Circle{
private:
    Point coord;
    double r;
public:
    Circle(Point p, double a): coord(p), r(a) {}
    int JudgeRelation(const Circle& another) {
        double d1 = r + another.r, d2 = fabs(r - another.r);
        double x1 = coord.x, y1 = coord.y;
        double x2 = another.coord.x, y2 = another.coord.y;
        if ( (x1 - x2)*(x1 - x2) + (y1 - y2)*(y1 - y2) > d1*d1 ) return 1;
        if ( (x1 - x2)*(x1 - x2) + (y1 - y2)*(y1 - y2) < d2*d2 ) return 2;
        if ( (x1 - x2)*(x1 - x2) + (y1 - y2)*(y1 - y2) == d1*d1 ) return 3;
        if ( (x1 - x2)*(x1 - x2) + (y1 - y2)*(y1 - y2) == d2*d2 ) return 4;
        if ( ((x1 - x2)*(x1 - x2) + (y1 - y2)*(y1 - y2) < d1*d1) && ((x1 - x2)*(x1 - x2) + (y1 - y2)*(y1 - y2) > d2*d2)) return 5;
 
    }
};

int main()
{
    int t, r, d, n;
    int x, y;
    cin >> t;
    while(t--) {
        cin >> r >> d;
        Point p(0,0);
        Circle c1(p,r);
        Circle c2(p,d);
        cin >> n;
        int cnt = 0;
        for(int i = 0; i < n; ++i) {
            cin >> x >> y >> r;
            Circle c3(Point(x,y),r);
            int flag1 = c1.JudgeRelation(c3);
            int flag2 = c2.JudgeRelation(c3);
            if((flag1 == 2 || flag1 == 4 ) && (flag2 == 1 || flag2 == 3)) cnt++;
        }
        cout << cnt << endl;
    }
    return 0;
}