A famous company in our country recruits people by asking them to solve problems without using C++ STL. Their problemset having problems on Searching Techniques, BFS, DFS, Tree Traversal, Prefix Tree or Trie , Backtracking and A glimpse of Dynamic Programming and many others.
Now I wonder how one can solve problems without STL. Like when using BFS how one can not using queue, vector, etc.
Can anybody please help me how to solve problems without STL?