def y(n):
if n == 1 or n == 2:
return 1
else:
return y(n-1)+y(n-2)
print(y(4))
>3
字符串反转
def rvs(s):
if s == '':
return s
else:
return rvs(s[1:])+ s[0]
m = 'wefsdfsdvbngh'
print(rvs(m))
>hgnbvdsfdsfew
汉诺塔
count =0
def y(n,start,end,mid):
if n == 1:
global count
count += 1
print('{}:{}->{}'.format(1,start,end))
else:
y(n-1,start,mid,end)
count += 1
y(n-1,mid,end,start)
print('{}:{}->{}'.format(n,start,end))
y(9,'a','b','m')
print(count)
import turtle as t
import time
def koch(size,n):
if n ==0:
t.fd(size)
else:
for i in [0,60,-120,60]:
t.left(i)
koch(size/3,n-1)
def main():
t.setup(800,600,100,100)
t.speed(100)
t.pencolor('red')
t.pensize(2)
t.penup()
t.goto(-300,0)
t.pendown()
koch(300,4)
t.left(-120)
koch(300,4)
t.left(-120)
koch(300,4)
t.hideturtle()
main()
time.sleep(5)