题目

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".

方法

题目的要求是输出Unix下的最简路径，Unix文件的根文件夹为"/"，"."表示当前文件夹，".."表示上级文件夹。

使用Stack来进行处理。

public String simplifyPath(String path) {    	Stack
      
        stack = new Stack
       
        ();    	String str = "";    	for (int i = 0; i < path.length(); i++) {    		if (path.charAt(i) == '/') {    			if (str.equals("..")) {    				if (!stack.isEmpty()) {    					stack.pop();    				}    			} else if (!str.equals(".") && !str.equals("")) {    				stack.push(str);    			}    			str = "";    		} else {    			str += path.charAt(i);    		}    	}    	if (str.equals("..")) {			if (!stack.isEmpty()) {				stack.pop();			}    	} else if (!str.equals(".") && !str.equals("")) {    		stack.push(str);    	}    	    	if (stack.isEmpty()) {    		return "/";    	}    	    	String re = "";    	while (!stack.isEmpty()) {    		re = "/" + stack.pop() + re;    	}    	return re;    }