# 478. Generate Random Point in a Circle (Medium)

https://leetcode.com/problems/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:

1. input and output values are in floating-point.
2. radius and x-y position of the center of the circle is passed into the class constructor.
3. a point on the circumference of the circle is considered to be in the circle.
4. `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]]```

Explanation of Input Syntax:

The input is two lists: the subroutines called and their arguments. `Solution`'s constructor has three arguments, the radius, x-position of the center, and y-position of the center of the circle. `randPoint` has no arguments. Arguments are always wrapped with a list, even if there aren't any.

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## Solutions

``````class Solution {

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

public double[] randPoint() {
double len = Math.sqrt(Math.random()) * r;
double deg = Math.random() * 2 * Math.PI;
return new double[]{len * Math.cos(deg) + x, len * Math.sin(deg) + y};
}
}

/**
* Your Solution object will be instantiated and called as such:
* Solution obj = new Solution(radius, x_center, y_center);
* double[] param_1 = obj.randPoint();
*/
``````