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".

思路：

用一个栈来实现，对特殊情况进行判断

代码：

 1     string simplifyPath(string path) {
 2         // IMPORTANT: Please reset any member data you declared, as
 3         // the same Solution instance will be reused for each test case.
 4         stack<string> Stack;
 5         while(true){
 6             if(path == "/")
 7                 break;
 8             int index = path.find('/', 1);
 9             string tmp;
10             if(index == -1){
11                 tmp = path.substr(1);
12                 path = "/";
13             }
14             else{
15                 tmp = path.substr(1, index-1);
16                 path = path.substr(index);
17             }
18             if(tmp == "")
19                 continue;
20             else if(tmp == ".."){
21                 if(!Stack.empty())
22                     Stack.pop();
23                 else
24                     continue;
25             }
26             else if(tmp != ".")   
27                 Stack.push(tmp);
28         }
29         string result = "";
30         if(Stack.empty())
31             return "/";
32         while(!Stack.empty()){
33             result = "/" + Stack.top() + result;
34             Stack.pop();
35         }
36         return result;
37     }