LeetCode 071-Simplify Path

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".

难度：中等

题目解析：通过正则表达式的分割，把/符号去掉，变成单一元素的数组。然后再逐个判断放入stack，但是要注意的是当元素为..的时候要把其前面的那个具体位置干掉

代码：

public class Solution {
    public String simplifyPath(String path) {
        
		 String[] elements=path.split("/+");
		 if(elements.length==0){
			 return "/";
		 }else{
			 Stack stack=new Stack();
			 for(int i=1;i<elements.length;i++){
				 if(elements[i].compareTo("..")!=0&&elements[i].compareTo(".")!=0){
					 stack.push(elements[i]);
				 }else if(elements[i].compareTo(".")!=0&&!stack.isEmpty()){
					 stack.pop();
				 }
			 }
			 StringBuffer buffer=new StringBuffer();
			 if(stack.isEmpty()){
				 buffer.append("/");
			 }else{
				 do{
				      buffer.insert(0, stack.pop());
					 buffer.insert(0, "/");
					
				 }while(!stack.isEmpty());
			 }
			 return buffer.toString();
		 }
	       
	    
    }
}