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recursion.py
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61 lines (47 loc) · 1.13 KB
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#!/usr/bin/env python
# encoding: utf-8
"""
@author: zhanghe
@software: PyCharm
@file: recursion.py
@time: 2017/6/17 下午4:26
@title: 递归实现阶乘
"""
def factorial(n):
print n
if n == 1:
return 1 # 递归结束
return n * factorial(n - 1) # 问题规模减1，递归调用
nodes = [
{'id': 1, 'parent': None},
{'id': 2, 'parent': 1},
{'id': 3, 'parent': 1},
{'id': 4, 'parent': 2},
{'id': 5, 'parent': 2},
{'id': 6, 'parent': 5},
{'id': 7, 'parent': 6},
{'id': 8, 'parent': 3}
]
node_list = []
def pop_list(nodes, parent=None, node_list=None):
"""
递归父子关系
:param nodes:
:param parent:
:param node_list:
:return:
"""
if parent is None:
return node_list
next_parent = None
node_list.append([])
for node in nodes:
if node['parent'] == parent:
node_list[-1].append(node)
if node['id'] == parent:
next_parent = node['parent']
pop_list(nodes, next_parent, node_list)
return node_list
print pop_list(nodes, 5, node_list)
if __name__ == '__main__':
print factorial(10)