leetcode 71. Simplify Path

参考：http://blog.youkuaiyun.com/makuiyu/article/details/44497901

题意

将linux下的路径名转换成一个与路径等价但最短的路径名

题解

使用栈来记录普通路径名（遇到“.”则跳过；“..”则出栈一个普通路径名）

代码

class Solution {
public:
    string simplifyPath(string path) {
        int len = path.length();
        stack<string> dirs;
        for(int i = 0; i < len;)
        {
            string temp;
            while(i < len && path[i] == '/')
                i++;
            while(i < len && path[i] != '/')
                temp += path[i++];
            if(temp == "..")
            {
                if(!dirs.empty())
                    dirs.pop();
            }
            else if(temp != "." && temp != "")
                dirs.push(temp);
        }
        string result = "";
        while(!dirs.empty())
        {
            result = "/" + dirs.top() + result;
            dirs.pop();
        }
        if(result == "")
            return "/";
        return result;
    }
};