71. Simplify Path

https://leetcode.com/problems/simplify-path/#/description

Given an absolute path for a file (Unix-style), simplify it.

For example,
path = "/home/", => "/home"
path = "/a/./b/../../c/", => "/c"

click to show corner cases.

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".

Sol :

In Unix, '..' means parent directory; '.' means current directory. 

Split the path using slash / and check the items. Append addresses and pop parent addresses.

class Solution(object):
    def simplifyPath(self, path):
        """
        :type path: str
        :rtype: str
        """
        stack = []
        for item in path.split("/"):
            if item not in [".", "..", ""]:
                stack.append(item)
            if item == ".." and stack:
                stack.pop()
        return "/" + "/".join(stack)

 Note:

 

1 string/list.split

 

 

 

ex. 

 

string = "www.gziscas.com.cn"

print(string.split('.'))

['www', 'gziscas', 'com', 'cn']

2 pop()

ex.

aList = [123, 'xyz', 'zara', 'abc'];

print "A List : ", aList.pop();
print "B List : ", aList.pop(2);

==>

A List :  abc
B List :  zara