478. Generate Random Point in a Circle
478. Generate Random Point in a Circle
Given the radius and x-y positions of the center of a circle, write a function randPoint which generates a uniform
random point in the circle.
Note:
input and output values are in floating-point.
radius and x-y position of the center of the circle is passed into the class constructor.
a point on the circumference of the circle is considered to be in the circle.
randPoint returns a size 2 array containing x-position and y-position of the random point, in that order.
Example 1:
Input:
["Solution","randPoint","randPoint","randPoint"]
[[1,0,0],[],[],[]]
Output: [null,[-0.72939,-0.65505],[-0.78502,-0.28626],[-0.83119,-0.19803]]
Example 2:
Input:
["Solution","randPoint","randPoint","randPoint"]
[[10,5,-7.5],[],[],[]]
Output: [null,[11.52438,-8.33273],[2.46992,-16.21705],[11.13430,-12.42337]]
- Give up illegal data points
class Solution {
double r, xc, yc;
Random random = new Random();
public Solution(double radius, double x_center, double y_center) {
r = radius;
xc = x_center;
yc = y_center;
}
public double[] randPoint() {
while(true) {
double x = random.nextDouble() * r * 2 - r;
double y = random.nextDouble() * r * 2 - r;
if(x * x + y * y <= r * r) {
return new double[]{xc + x, yc + y};
}
}
}
}