简化路径（stringstream+getline）

题目：https://leetcode-cn.com/problems/simplify-path/ 参考：https://leetcode-cn.com/problems/simplify-path/solution/cli-yong-stringstreamhe-getlinefen-ge-zi-fu-chuan-/

class Solution {
public:
    string simplifyPath(string path) {
    	/*
		*利用getline,每次以/为分隔符
		*
		*/
        stringstream is(path);
        vector strs;
        string res = "", tmp = "";
        while(getline(is, tmp, '/')) {
            if(tmp == "" || tmp == ".")
                continue;
            else if(tmp == ".." && !strs.empty())
                strs.pop_back();
            else if(tmp != "..")
                strs.push_back(tmp);
        }
        for(string str:strs) 
            res +=  "/" + str;
        if(res.empty())
            return "/";
        return res;
    }
};