478. randomly generate points in a circle

478. Randomly generate points in a circle

Today's daily question is to randomly generate points in a circle , The difficulty is medium , The specific methods are as follows

1. Scatter point samples in the circumscribed rectangle of the circle .
2. If the sampled point is within a circle , return ; Otherwise, resample .
3. Because every dimension of two dimensions is uniformly distributed , So the results are uniformly distributed .

class Solution {
    
private:
    double r, x, y;

public:
    Solution(double radius, double x_center, double y_center) {
    
        r = radius;
        x = x_center;
        y = y_center;
    }

    vector<double> randPoint() {
    
        while (1) {
    
            double cx = 2 * r * rand() / RAND_MAX - r + x;
            double cy = 2 * r * rand() / RAND_MAX - r + y;
            if ((cx - x) * (cx - x) + (cy - y) * (cy - y) <= r * r)
                return {
    cx, cy};
        }
    }
};