能跑得起来，但是结果不对，所有的“点在圆内”的情况都被算成了“点在圆上”，这是为什么呢？

Question

#include <iostream>
#include<string>;
using namespace std;

class point
{
private:
    double x;
    double y;
public:
    void cinX(double a) {
        x = a;
    }
    double getX() {
        double a = x;
        return a;
    }
    void cinY(double b) {
        y = b;
    }
    double getY() {
        double a = y;
        return a;
    }
};

class circle {
private:
    double rX;
    double rY;
    double r;
public:
    void cinrX(double a) {
        rX = a;
    }
    double getrX() {
        double x = rX;
        return x;
    }
    void cinrY(double a) {
        rY = a;
    }
    double getrY() {
        double a = rY;
        return a;
    }
    void cinr(double a) {
        r = a;
    }
    double getr() {
        double a = r;
        return a;
    }
};
double getDistance(point p, circle c) {
    double d = sqrt((p.getX() - c.getrX()) * (p.getX() - c.getrX()) + (p.getY() - c.getrY()) * (p.getY() - c.getrY()));
    return d;
}
int main()
{
    point p1;
    p1.cinX(2);
    p1.cinY(2);
    circle c1;
    c1.cinrX(4);
    c1.cinrY(5);
    c1.cinr(30);
    double d = getDistance(p1, c1);
    cout << "d = " << d << endl;
    if (d > c1.getr())
    {
        cout << "点在圆外" << endl;
        return 0;
    }
    else {
        if (d = c1.getr()) {
            cout << "点在圆上" << endl;
            return 0;
        }
        else
            cout << "点在圆内" << endl;
    }
}

Answer 1

点在圆上判断有问题，应该是==