Simplify Path [LeetCode]

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".

Summary: Very careful about corner cases, like "/", "/.", "..". 

class Solution {
public:
    void handleEntry(vector<string> &path_stack, string path_entry) {
        if(path_entry == "..") {
            if(path_stack.size() > 0)
                path_stack.pop_back();
        }else if (path_entry != ".") 
                path_stack.push_back(path_entry);
    }
    
    string simplifyPath(string path) {
        string simple_path;
        if(path.size() == 0)
            return simple_path;
        vector<string> path_stack;
        string path_entry;
        for(int i = 0; i < path.size(); i ++) {
            if(path_entry.size() == 0 && path[i] == '/'){
                continue;
            }else if (path_entry.size() != 0 && path[i] == '/') {
                handleEntry(path_stack, path_entry);
                path_entry.clear();
            }else {
                path_entry.push_back(path[i]);
            }
        }
        if(path_entry.size() > 0)
            handleEntry(path_stack, path_entry);
    
        for(string item: path_stack) {
            simple_path += "/";
            simple_path += item;
        }
        if(simple_path.size() == 0)
            return "/";
        return simple_path;
    }
};