原题地址:https://oj.leetcode.com/problems/simplify-path/
题意:
Given an absolute path for a file (Unix-style), simplify it.
For example,
path = "/home/"
,
=> "/home"
path = "/a/./b/../../c/"
,
=> "/c"
Corner Cases:
- Did you consider the case
where path ="/../"
?
In this
case, you should return"/"
. - Another corner case is the path might contain multiple
slashes‘/‘
together, such
as"/home//foo/"
.
In this case, you should ignore
redundant slashes and return"/home/foo"
.
解题思路:
题目的要求是输出Unix下的最简路径,Unix文件的根目录为"/","."表示当前目录,".."表示上级目录。
例如:
输入1:
/../a/b/c/./..
输出1:
/a/b
模拟整个过程:
1. "/" 根目录
2. ".." 跳转上级目录,上级目录为空,所以依旧处于 "/"
3. "a" 进入子目录a,目前处于 "/a"
4. "b" 进入子目录b,目前处于 "/a/b"
5. "c" 进入子目录c,目前处于 "/a/b/c"
6. "." 当前目录,不操作,仍处于 "/a/b/c"
7. ".." 返回上级目录,最终为 "/a/b"
使用一个栈来解决问题。遇到‘..‘弹栈,遇到‘.‘不操作,其他情况下压栈。
代码一:
class Solution:
# @param path, a string
# @return a string
def simplifyPath(self, path):
stack = []
i = 0
res = ‘‘
while i < len(path):
end = i+1
while end < len(path) and path[end] != "/":
end += 1
sub=path[i+1:end]
if len(sub) > 0:
if sub == "..":
if stack != []: stack.pop()
elif sub != ".":
stack.append(sub)
i = end
if stack == []: return "/"
for i in stack:
res += "/"+i
return res
代码二:
利用python的字符串处理能力。
class Solution:
# @param path, a string
# @return a string
def simplifyPath(self, path):
path = path.split(‘/‘)
curr = ‘/‘
for i in path:
if i == ‘..‘:
if curr != ‘/‘:
curr = ‘/‘.join(curr.split(‘/‘)[:-1])
if curr == ‘‘: curr = ‘/‘
elif i != ‘.‘ and i != ‘‘:
curr += ‘/‘ + i if curr != ‘/‘ else i
return curr
[leetcode]Simplify Path @ Python,布布扣,bubuko.com
时间: 2024-10-10 09:10:22