python学习-循环

1.正序循环

def xunhuan(i):
    if i<10:
        print(i)
    else:
        return
    xunhuan(i+1)

if __name__=="__main__":
    xunhuan(1)

2.倒叙循环

def xunhuan(i):
    if i<10:
        xunhuan(i+1)
        print(i)
    else:
        return


if __name__=="__main__":
    xunhuan(1)

3.九九乘法表

def jiujiu(n):
    if n<10:
        for i in range(1,n+1):
            print ("%d*%d=%d"%(i,n,i*n),end="t")
        print()
        jiujiu(n+1)


if __name__=="__main__":
    jiujiu(1)

非递归版本

def jiujiu():
    for k in range(1,10):
        for i in range(1,k+1):
            print ("%d*%d=%d"%(i,k,i*k),end="t")
        print()
        # jiujiu(n+1)


if __name__=="__main__":
    jiujiu()

4.斐波那契数列

def f(n):
    if n>1:
        return f(n-1)+f(n-2)
    else:
        return 1

if __name__=="__main__":
    for i in range(0,10):
        print(f(i))

非递归版

def f(n):
    if n>1:
        a=1
        b=1
        fibN=0
        for i in range(2,n+1):
            fibN=a+b
            a=b
            b=fibN
        return fibN
    else:
        return 1

if __name__=="__main__":
    for i in range(0,10):
        print(f(i))

5.舍罕王赏麦

def f(n):
    if n>1:
        sum,k=f(n-1)
        k=k*2
        sum=sum+k
        return sum,k

    else:
        return 1,1



if __name__=="__main__":
    print(f(64))