Added solution of Simplify Path in cpp

Author: AkashSingh19

71.Simplify Path.cpp

@@ -0,0 +1,15 @@
+class Solution {
+public:
+   string simplifyPath(string path) {
+    string res, tmp;
+    vector<string> stk;
+    stringstream ss(path);
+    while(getline(ss,tmp,'/')) {
+        if (tmp == "" or tmp == ".") continue;
+        if (tmp == ".." and !stk.empty()) stk.pop_back();
+        else if (tmp != "..") stk.push_back(tmp);
+    }
+    for(auto str : stk) res += "/"+str;
+    return res.empty() ? "/" : res;
+}
+};