How do you debug algorithms before submitting to a competition?

1 Use test cases

One of the most basic and effective ways to debug algorithms is to use test cases. Test cases are inputs and outputs that you can use to check if your algorithm produces the expected results. You can use the test cases provided by the problem statement, or you can create your own test cases based on the problem specifications and edge cases. You can run your algorithm on the test cases using an online IDE, a local IDE, or a command-line tool. You can also use a debugger tool to step through your code and inspect the values of variables and expressions. By using test cases, you can identify and fix errors in your logic, syntax, or implementation.

2 Use print statements

Another simple and useful way to debug algorithms is to use print statements. Print statements are statements that print out the value of a variable, an expression, or a message to the standard output. You can use print statements to track the flow of your algorithm, to monitor the changes in your data structures, or to verify the correctness of your calculations. You can also use print statements to compare the output of your algorithm with the expected output, or to find out where your algorithm fails or crashes. By using print statements, you can gain insight into how your algorithm works and where it needs improvement.

3 Use assertions

A more advanced and powerful way to debug algorithms is to use assertions. Assertions are statements that check if a condition is true, and raise an error if it is false. You can use assertions to enforce the assumptions and invariants of your algorithm, to validate the input and output of your functions, or to test the performance and complexity of your algorithm. You can also use assertions to catch exceptions and handle errors gracefully. By using assertions, you can make your algorithm more robust and reliable, and avoid unexpected or undesired behavior.

4 Use online tools

Debugging algorithms is a great way to improve your coding and problem-solving abilities. To make it easier and more convenient, you can use online tools. These include compilers and interpreters, debuggers, visualizers, analyzers, and validators. With these tools, you can run and test your code in different programming languages and environments, set breakpoints, watch variables, trace execution, see data structures, check syntax and style, verify correctness and efficiency against test cases, and access various resources and feedback. By using the tips and techniques we discussed in this article, you can debug your algorithm before submitting it to avoid common mistakes and pitfalls. So happy coding!

5 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?