全班50个人，俩个人生日在同一天的概率是？Java

package helloworld;
import java.util.Random;
public class hello {
        public static void main(String[] args) {
            for(int i = 0; i < n; ++i){
                boolean[] p = new boolean[365];
                for(int j = 0; j < 365; ++j) p[j] = false;
   
                for(int k = 0; k < 50; ++k){
                    Random r = new Random();
                    int x = r.nextInt(365);
                    if(p[x]) {
                        cnt++;
                        break;
                    }
                    else p[x] = true;
                }
            }
            System.out.println(cnt * 1.0 /n);
        } 
        static int cnt = 0;
        static int n = 10000;
}