Is there any websites / Android Applications which will teach me each and every ( old as well as new ) concepts of c++??

Question

This application or website will teach this concepts in increasing order of understanding. From Variable declaration to vectors, hashmap, inbuilt tree and graph declaration and how to use them, inbuilt header files ( e.g. <algorithm>, <map>, <tree> etc.) necessary for competitive coding such as Codechef, Google Hashcode, Kickstart, Code Jam, etc.

Answer 1

To learn everything single thing there is about c++, check out the docs:
https://devdocs.io/cpp/

And organize it to fit your liking.

Let me explain:

Two things, really,

There is not single website to learn everything about c++. You'll need to combine various sources and build up your knowledge. And of course practice a whole lot.

And second,
you don't have to know everything there is to know about c++. You'll go crazy. You should learn a bunch of algorithms instead. And how and where and why to implement them. That'll help you go very far if you master them for completive coding

But since you asked nicely:
"Competitive Programming" by Steven and Felix Halim.
This is a book. Heard it's pretty good

Check out TutorialsPoint. It's pretty thorough. And the docs too.