String Searching – The Knuth-Morris-Pratt Algorithm


We’ve seen how to do the naive approach towards pattern matching. So what about other algorithms that are much more better at doing this task? This is the Knuth-Morris-Pratt (KMP) algorithm for pattern matching.

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String Searching – The Naive Approach


We all should all know what string searching is. We have a pattern p and some string s, and we wish to see if p exists in s. There are a number of ways to do this, and this is one of those many ways; the naive approach.

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Algorithms – The 0/1 Knapsack Problem – Dynamic Programming method


Okay, I didn’t see that James had made a video about the very same subject. Great minds think alike I guess? Sigh. Well, here it is: The Dynamic Programming method for solving a 0/1 Knapsack Problem explained, in depth, by me in under 11 minutes!

Bug 1: Ignore the “The cell with the green circle around has a capacity of” blah blah etc. because I uploaded the wrong version ._. The green circle should be around cell (3,1).
Bug 2: I circle item ‘1’ when I should circle item ‘3’ at the end when we’re going through the keep array. I fail.
Bug 3: I say ‘2’ somewhere instead of ‘3’. See if you can spot it.

Sorting – Quick Sort


A post dedicated to that oh so famous, Quick sort! ^^

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Sorting – Merge Sort


A post all about the Merge sort 😀

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Algorithms – Quick Graph Terminology


This post will be brief. It just contains a load of terminology for parts of graphs, such as:

  • Spanning Trees
  • Back Edges
  • etc…

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Dynamic Programming – Solving The Knapsack Problem


How do we fit the most valuable items from a selection of items into a knapsack? This… ladies and gentlemen, is the Knapsack problem.

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Algorithms – Traversals


Traversals

What is a traversal? It’s when you visit every node of a tree or graph using the edges.

Tree traversal

Let’s talk about 3 methods of traversing trees (Note: Always start at the root)

  • Depth-First-Search: Visit all the descendants of a node before visiting the sibling nodes. You have to visit some nodes more than once in a DFS, this is called backtracking
  • Breadth-First-Search: Visit all children of a node before visiting sibling nodes
  • Priority Search: Nodes are given priorities, and the children of the node that haven’t been visited yet with the highest priority are visited first

So let’s try these on a tree. Here’s one I made earlier: Read more of this post

Algorithms – More graphs


More Graphs (yay)

Note: This is a direct follow on (or a sequel if you want) to this post, so you might want to read that first!

Representing graphs

So you’ve seen what graphs are and how they can be classified. But how do you represent them in code? For example, do we put them in an array, a vector or a linked list? There isn’t one definite answer, so let’s go through some of the methods of representing them. Read more of this post

Algorithms – Intro to Graphs


Intro to Graphs

What are graphs?

So while you might think that graphs are things like these:

..you’re right! That is a graph. But when computer scientists talk about graphs, they actually mean these: Read more of this post