Coding Concept - Algorithms

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An algorithm uses a series of steps to determine an outcome. Steps can be a set of directions, comparisons, or even a mathematical formula.

Your daily life is full of algorithms that you use without thinking about it. They help you make decisions, create things, and solve problems.

Real life examples:

  • Checking if you have enough money to buy a snack.
  • Getting dressed in the morning.
  • Drawing stick figures.

Coding examples:

  • Checking if a skill level is high enough to use an item.
  • Sorting a list of items into alphabetical order.
  • A player standing on lava loses 5 health every second. If they reach 0, they respawn.

Creating Algorithms in Code

In real life, we don't usually think about the algorithms we use everyday. Computers however, need algorithms to be coded step-by-step and use at least one of three methods to solve a problem or produce an outcome.

MethodologyExample
Selection - Uses conditional statements such as if/then to determine an output.

if time == 0 then
stopLightColor = red
end

Sequencing - A set of precise steps.


local function createBridge()
create new block
size block
set color
rotate
set location
parent to workspace
end

Iteration - Repeats parts of the code as necessary, such as in for loops or multiplication.


for countDown = 10, 1, -1 do
time -= 1
task.wait(1)
end

Combining Algorithms

Much like larger problems can be broken into smaller problems, some algorithms can be broken down into a series of smaller algorithms.

Think of your real-life morning time algorithm to get dressed. If that's your main algorithm, it might use one algorithm for picking out your clothes, and a second algorithm for putting clothes on.

Getting Dressed Pseudocode

-- First algorithm for picking clothes
local function pickClothes()
pick top clothing
pick bottom clothing
pick Socks
pick Shoes
end
-- Second algorithm for putting clothes on
local function putOnClothes()
put on top clothing
put on bottom clothing
put on socks
put on shoes
end
-- Main algorithm, calls pickClothes()and putOnClothes()
local function getDressed()
pickClothes()
putOnClothes()
end

Summary

Algorithms are predefined steps that provide an outcome. In daily life, algorithms solve problems like getting dressed, going to work, or making a cake. In code, algorithms solve problems like managing websites, handling traffic congestion, or running game mechanics. To complete their goal, algorithms will often call on other algorithms.

Algorithms use three different ways to come to a conclusion; selection, iteration, and sequencing. Selection uses conditionals such as if/then statements. Iteration repeats parts of the code as necessary. Sequencing uses a series of steps to produce a result.