假设,一级台阶,有f(1)种方法,二级台阶有f(2)种方法,以此类推,跳到n级台阶有f(n)种方法。
能够看出,f(1) = 1,f(2) = 2。那么,n级台阶就有两种状况。python
跳1级,接下来是f(n - 1)code
跳2级,接下来是f(n - 2)class
总数就是f(n) = f(n - 1) + f(n - 2)方法
def memo(func): cache = {} def inner(*args, **kwargs): if args not in cache: cache[args] = func(*args, **kwargs) return cache[args] return inner @memo def fbi(n): if n <= 2: return 1 return fbi(n - 1) + fbi(n - 2) print(fbi(100))
def memo(func): cache = {} def inner(*args, **kwargs): if args not in cache: cache[args] = func(*args, **kwargs) return cache[args] return inner @memo def fbi(n): if n <= 2: return 1 return 2 * fbi(n - 1) print(fbi(100))