About Cody

Getting Started

Browsing Problems

On the Problems page there are two problem groups: Community and Cody Challenge. The Community group contains all problems contributed by Cody players. The Cody Challenge group starts with three problems added by the Cody administrator and unlocks more problems as you solve them. You can browse or solve problems in either group.

Solving Problems

When you see an interesting problem, click the Solve This Now! button. Don't worry about hurting your score or your pride by submitting an incorrect answer. Other players do not see your name with an incorrect solution, nor does it affect your score.

Let's say you choose to solve this problem in the Community Challenge group:

Cody always gives you a starting point, or function template. In this case, the function template is

function y = plus_one(x)
    y = x;
end

The function template does not return the correct answer; in this example, you need to add +1 to make it work, as shown below.

function y = plus_one(x)
    y = x+1;
end

When you submit this code, you will get the correct answer. Now try your hand at another problem.

Understanding Solution Size

Cody uses a node-count calculation to determine the solution size based on the number of nodes in the parse tree. Think of size as code length. Writing succinct code earns you a better result. Comments do not contribute to code size.

To illustrate how Cody determines size, here are two solutions to the plus-one problem. Solution 1 has a size of 12. Solution 2 has a size of 16. Both functions return the correct answer, but the first solution provides the better score due to its smaller size.

Solution 1: size 12

function y = plus_one(x)
    y = x+1;
end

Solution 2: size 16

function y = plus_one(x)
    z = x;
    y = z+1;
end

You can find the official scoring code on File Exchange.

Contributing Problems

Any Cody player can Challenge others by adding problems to the Community group. If you have a problem without a solution in mind or are looking for a better idea how to solve it, post it in the Community group and see what other players come up with.

Note: Cody does not handle graphical problems yet.

Provide a function template to help players get started. You also need to write tests to validate players' solutions. You can also provide your own solution to validate your tests. Give it a try!

Finding Solutions Using Directives

Search directives help you find Cody solutions. From the Solutions page, specify search directives in the search box.

Solution Result	Directive	Examples
Player with this name	player:	player:'Ned'
Player with this ID number	player_id:	player_id:140947
Problem with this ID number	problem_id:	problem_id:1
Solution with this size	size:	size:20
Solution size with this range	size_range:	size_range:10-20