LeetCode Simplify Path

题目：

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) {
		stack<string> t;
		int n = path.size();
		int i = 0;
		while (i < n) {
			if (path[i] == '/')
				i++;
			string s;
			while (path[i] != '/' && i < n) {
				s.push_back(path[i]);
				i++;
			}
			if (s == "." || s == "")
				continue;
			else if (s == "..")  {
				if (!t.empty())
					t.pop();
			}
			else
				t.push(s);
		}
		if (t.empty())
			return "/";
		string ans;
		while (!t.empty()) {
			ans = "/" + t.top() + ans;
			t.pop();
		}
		return ans;
	}
};