Simplify Path

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".

class Solution {
public:
    string simplifyPath(string path) {
        // Start typing your C/C++ solution below
        // DO NOT write int main() function
        deque<string> dq;
        if(path.size() < 1){
            return path;
        }
        if(path == "/"){
            return path;
        }
        string ans;
        if(path[0] == '/'){
            ans = "/";
        } else {
            return "";
        }
       
        int i, j;
        for(i = 1; i < path.size(); i++){
            string tmp="";
            for(j = i; j < path.size(); j++){
                if(path[j]!= '/'){
                    tmp += path[j];
                } else {
                    break;
                }
            }
            if(tmp == ""){
                i = j;
            } else if(tmp == "."){
                i = j;
            } else if(tmp == ".."){
                if(!dq.empty()){
                    dq.pop_back();
                }
                i = j;
            } else {
                dq.push_back(tmp);
                i = j;
            }
        }
        ans = "/";
        int first = true;
        while(!dq.empty()){
            if(first){
                first =false;
            } else {
                ans+="/";
            }
            ans+=dq.front();
            dq.pop_front();
        }
        return ans;
    }
};