This discussion is for expanding your array of maneuvers needed to code quickly and efficiently.

STL:

The first and most important thing that I'd like to discuss about is the C++ STL. Learning it would enable you to code up an assortment of algorithms and complicated data structures in a matter of seconds.

You can learn to use the C++ STL from the following amazing sites:

Studytonight : Contains syntax and examples for most of the STL containers and algorithms.

Sanfoundry : Shows how to implement what you've learnt in complete programs

Topcoder(Highly recommended) : This place teaches yo...

I recommend watching the following videos for learning about graphs. These are really well made videos and he covers a lot in these short videos, so if you feel overwhelmed, use the rewind and pause buttons.

Introduction to Graphs

What are graphs? What are different types of graphs (directed and undirected, trees and DAGs, etc)? And examples of using them to model web links, flights between cities, and other things.

Video for concept and walkthrough

First, let's watch a slow-paced easy-to-follow walkthrough of the breadth-first search and depth-first search algorithms.

The motivation for binary indexed trees is similar to that of segment trees. However, note that segment trees are much more flexible than binary indexed trees, and usually its true that any problem that can be solved with BIT can be solved with segment trees but not the other way around.

Video tutorial: This is a superb tutorial, giving the motivation, walking through example, and going step-by-step through the pseudocode.

Prerequisites: Matrix in algebra, Matrix multiplication

Introduction: Matrix Exponentiation (also known as matrix power, repeated squaring) is a technique used to solve linear recurrences. This technique is very useful in competitive programming when dealing with linear recurrences (appears along Dynamic Programming). This technique also solves a lot of problems in graph theory. Only solving recurrences is covered here, applications on graph theory will be discussed later.

Video tutorial: This video shows how you can use matrices to calculate the n-th fibonacci number (where n is very large ~10^18). You should be able to understand the technique after watching this video. Exercises will be added soon.