java O(2^N) 算法示例
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Example of a O(2^N) algorithm
提问by developer
I've been told that
有人告诉我
O(2^N) denotes an algorithm whose growth will double with each additional element in the input data set
O(2^N) 表示一种算法，其增长将随着输入数据集中每增加一个元素而加倍
Can someone provide an example that behaves like this?
有人可以提供一个行为像这样的例子吗？
回答by axtavt
Recursive computation of Fibonacci numbers is a good example of O(2N) algorithm (though O(2N) is not a tight bound for it):
斐波那契数的递归计算是 O(2 N) 算法的一个很好的例子（尽管O(2 N) 不是它的严格界限）：
public int fib(int n) {
if (n <= 1) return n;
else return fib(n - 2) + fib(n - 1);
}
