Java 递归算法分析：计算递归调用次数

public class Main {\n static int ans = 0;\n\n public static void main(String[] args) {\n int n = 9;\n recursion(n);\n System.out.println(ans);\n }\n\n public static void recursion(int n) {\n if (n == 0) {\n ans++;\n return;\n }\n recursion(n-1);\n }\n}