java中的递归
给定此方法调用:
public class MainClass { public static void main(String[] args) { System.out.println(fib(3)); } private static int fib(int i) { System.out.println("Into fib with i = " + i); if (i < 2) { System.out.println("We got here"); return i; } return fib(i-1) + fib(i-2); } }
我期望:
* fib(i-1) to return 2 * fib(i-2) to return 1 * return 2 + 1 to return 3
结果:
2
这是控制台的输出:
Into fib with i = 3 Into fib with i = 2 Into fib with i = 1 We got here Into fib with i = 0 We got here
我理解这一部分的一切:
Into fib with i = 0
我什么时候可以0?
fib(3)
称为fib(2)
。 当你调用fib(2)
,它将调用fib(i-1)
和fib(i-2)
,即fib(1)
和fib(0)
。