Simplify Path

题意：简化UNIX风格的文件路径，如：

path = “/home/”, => “/home”
path = “/a/./b/../../c/”, => “/c”

思路：将两个/之间的字符串放在一个vector里，遇到”/”、“.."和”.”特殊处理下，最后格式化输出

代码：

string simplifyPath(string path) {

        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        vector<string> pathes;
        string seg = "";
        for(int i = 0; i <= path.size(); ++i) {
            if(i == path.size() || path[i] == '/') {
                if(seg == "..") {
                    if(pathes.size() > 0) {
                        pathes.pop_back();
                    } else {
                        //return "/";//error, in the test set, this case just ignore
                    }
                } else if(seg == ".") {
                    //do nothing
                } else if(seg.size() > 0) {
                    pathes.push_back(seg);
                }
                seg = "";
            } else {
                seg += path[i];
            }
        }
        string ret="/";
        for(int i = 0; i < pathes.size(); ++i) {
            if(i>0) ret += "/";
            ret += pathes[i];
        }
        return ret;
    }