def fact(n):
if n <= 1:
return 1
else:
return n * fact(n - 1)
- 斐波那契数列: 第0项是0,第1项是1,从第2项开始,每一项都等于前两项之和
def fib(n):
i = 2
arr = [0, 1]
while n > 2:
arr.append(arr[i - 1] + arr[i - 2])
n -= 1
i += 1
return arr
//
MemoTable = {}
def MemoizedFib(n):
if n <= 2:
return 1
if n in MemoTable:
return MemoTable[n]
MemoTable[n] = MemoizedFib(n-1) + MemoizedFib(n-2)
return MemoTable[n]
def sqrt(x):
def average(a, b):
return (a + b) / 2.0
def is_good_enough(guess):
return (abs((guess * guess) - x) < 0.001)
def improve(guess):
return average(guess, x / guess)
def sqrt_iter(guess):
if is_good_enough(guess):
return guess
else:
return sqrt_iter(improve(guess))
return sqrt_iter(1.0)
def gcd(x, y):
result = x
if y != 0:
result = gcd(y, x % y)
return result
def TowerOfHanoi(n, a, b, tmp):
if n == 1:
b.append(a.pop())
else:
TowerOfHanoi(n-1, a, tmp, b)
b.append(a.pop())
TowerOfHanoi(n-1, tmp, b, a)
stack1 = [4,3,2,1]
stack2 = []
stack3 = []
TowerOfHanoi(len(stack1), stack1, stack3, stack2)
def map(func, lst):
if lst == []:
return []
else:
return [func(lst[0])] + map(func, lst[1:])
def halveElements(lst):
return map(lambda x: x / 2.0, lst)
input = [2, 4, 6, 8, 10]
output = halveElements(input)
def summation(low, high, f, next):
s = 0
x = low
while x <= high:
s = s + f(x)
x = next(x)
return s
def sumsquares(low, high):
return summation(low, high, lambda x: x**2, lambda x: x+1)