71.Simplify Path¶
Tags:Medium
Stack
Link: https://leetcode.com/problems/simplify-path/
Given an absolute path for a file (Unix-style), simplify it. Or in other words, convert it to the canonical path.
In a UNIX-style file system, a period .
refers to the current directory. Furthermore, a double period ..
moves the directory up a level. For more information, see: Absolute path vs relative path in Linux/Unix
Note that the returned canonical path must always begin with a slash /
, and there must be only a single slash /
between two directory names. The last directory name (if it exists) must not end with a trailing /
. Also, the canonical path must be the shortest string representing the absolute path.
Example 1:
Input: "/home/"
Output: "/home"
Explanation: Note that there is no trailing slash after the last directory name.
Example 2:
Input: "/../"
Output: "/"
Explanation: Going one level up from the root directory is a no-op, as the root level is the highest level you can go.
Example 3:
Input: "/home//foo/"
Output: "/home/foo"
Explanation: In the canonical path, multiple consecutive slashes are replaced by a single one.
Example 4:
Input: "/a/./b/../../c/"
Output: "/c"
Example 5:
Input: "/a/../../b/../c//.//"
Output: "/c"
Example 6:
Input: "/a//b////c/d//././/.."
Output: "/a/b/c"
Answer:
class Solution {
public:
string simplifyPath(string path) {
string res, tmp;
vector<string> stk;
stringstream ss(path);
while(getline(ss,tmp,'/')) {
if (tmp == "" or tmp == ".") continue;
if (tmp == ".." and !stk.empty()) stk.pop_back();
else if (tmp != "..") stk.push_back(tmp);
}
for(auto str : stk) res += "/"+str;
return res.empty() ? "/" : res;
}
};
解析:本质相当于应用split函数,只不过通过stringstream和getline代替了