[leetcode] Simplify Path

题目：

Given an absolute path for a file (Unix-style), simplify it.

For example,
path = 

"/home/"

, => 

"/home"

path = 

"/a/./b/../../c/"

, => 

"/c"

click to show corner cases.

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"

.

代码：
class Solution {
public:
/***
* 注意几个细节：
* 1)重复连续出现的'/'，只按1个处理，即跳过重复连续出现的'/'；
* 2)如果路径名是"."，则不处理；
* 3)如果路径名是".."，则需要弹栈，如果栈为空，则不做处理；
* 4)如果路径名为其他字符串，入栈。
*
*
* */
string simplifyPath(string path) {
int size = path.size();
stack<string> ss;
for(int i = 0; i < size;){
//跳过'/'
while('/' == path[i] && i < size)
++ i;
//记录路径名称
string s = "";
while('/' != path[i] && i < size)
s += path[i ++];
//对当前路径进行处理
if(s == ".." && !ss.empty())
ss.pop();
else if(s != "" && s!= "." && s != "..")
ss.push(s);
}
string res = "";
if(ss.empty())
return "/";
else{
//注意输出顺序
while(!ss.empty()){
res = "/" + ss.top() + res;
ss.pop();
}
}
return res;

}
};