题目

原题在此
Given a string path, which is an absolute path (starting with a slash '/') to a file or directory in a Unix-style file system, convert it to the simplified canonical path.

In a Unix-style file system, a period '.' refers to the current directory, a double period '..' refers to the directory up a level, and any multiple consecutive slashes (i.e. '//') are treated as a single slash '/'. For this problem, any other format of periods such as '...' are treated as file/directory names.

The canonical path should have the following format:

The path starts with a single slash '/'.
Any two directories are separated by a single slash '/'.
The path does not end with a trailing '/'.
The path only contains the directories on the path from the root directory to the target file or directory (i.e., no period '.' or double period '..')
Return the simplified canonical path.

解析

将字符串以'/'为界分开遍历, 是'..'就退栈; 是空串(连续的两个’/‘分隔的结果)或’.’就不作处理, 其他情况就入栈. 最后将栈内元素全部join再一起.

代码

rust

impl Solution {
    pub fn simplify_path(path: String) -> String {
        let mut stack = vec![];
        for p in path.split("/") {
            if p == "." || p == "" {
                continue;        
            } else if p == ".." {
                stack.pop();
            } else {
                stack.push(p);
            }
        }
        format!("/{}", stack.join("/"))
    }
}