Here’s the video where I discuss the same content: "I could have gotten that if I just had more time", How to get those points!
With the USACO December contest on the horizon, it's crucial to delve deeper into a crucial aspect of competitive programming: content strategy. Often overshadowed by the focus on algorithms and data structures, content strategy and implementation skills play an indispensable role in achieving high scores. In this comprehensive guide, we'll explore the intricacies of content strategy, its impact on your performance, and actionable tips to help you excel in implementing and debugging. Let's dive into the world of content strategy, demystify its components, and unlock its potential for success.
The Significance of Contest Strategy
To underscore the importance of content strategy, it's worth noting that in USACO camp, there is a dedicated lecture to it. This commitment to content strategy underlines its important role in competitive programming. As a coach, I firmly believe in its significance, having witnessed countless instances where content strategy transformed a participant's performance; I’ve even seen situations where a participant took their score from a 233 to a whopping 833 after mastering an effective contest strategy, securing them a spot in Gold!
Understanding the Contest Log
At the heart of contest strategy lies the concept of a contest log. It serves as your compass during the contest, helping you navigate the treacherous waters of problem-solving with precision and efficiency. The contest log is your strategic tool to optimize time management and prioritize tasks effectively.
To create a contest log, break down your contest time into 15-minute increments. At the end of each interval, record what you've been doing. These entries can be as simple as "thinking about P2" to indicate you were thinking about the second problem, "implementing P2" for coding the third problem, or "debugging P1" when looking for where your code goes wrong in the first problem.
Initially, some may find this task distracting, fearing it will disrupt their focus. However, the opposite is true. A few words won't significantly divert your concentration, but they will provide valuable insights. For instance, you might fall through the dangerous path of continuously saying “I’m so close!”, and tunnel vision on debugging. Without the contest log, you might unknowingly squander hours on a single problem.
Identifying Time Leaks
The contest log functions as a time leak detector. It reveals instances where you've unknowingly spent excessive time on a problem. During the excitement of a contest, it's easy to lose track of time. However, the contest log keeps you grounded, making you aware of time leaks that may have otherwise gone unnoticed.
By being conscious of how you allocate your time, you can make more informed decisions. Consider this scenario: you realize you've invested an hour and a half in debugging problem 2. With this awareness, you can choose to cut your losses and allocate the next 30 minutes to other problems. This strategic shift can be the difference between securing partial credit on multiple problems or being stuck in a debugging trench.
Leveraging Task Switching
An important part of a good content strategy is task switching. It involves periodically shifting your focus between different problems. This technique often leads to fresh insights and breakthroughs when you return to a problem after working on others.
To implement task switching effectively, set a rule for yourself: do not spend more than 30 minutes coding or debugging any single problem at the contest's outset. This ensures that you allocate time to every problem, giving you the opportunity to secure partial credit on each. This is especially important for the bronze, silver, and gold divisions, as the goal is to solve two to two and a half problems, emphasizing the significance of partial credits.
Incorporating task switching into your strategy can lead to remarkable results. It's not uncommon for students to return to a problem and suddenly grasp its solution after working on different tasks. The fresh perspective gained through task switching can be a game-changer.
Reading All Problems
Before immersing yourself in coding, invest a minute in reading all the problems thoroughly. While the temptation is strong to begin coding immediately, this approach can be counterproductive. Rushing into problem 1, assuming it's the easiest, might lead to frustration when you realize that it is actually the hardest problem.
By taking the time to read all the problems, you gain a holistic view of the contest. This approach allows you to identify the genuinely easiest problem. Ranking problems from easiest to hardest enables you to tackle the most manageable ones first.
Shortening Implementation Time
When solving problems, always keep in mind the split between the time you come up with the idea, and the time you take to implement. What should you do when you can come up with the ideas relatively quickly, but take many hours to implement, and even longer to debug? I discuss this issue specifically here.
How much time should you aim for?
For problems in the silver divisions and above, dedicating 40 minutes to thinking and 40 minutes to implementing and debugging is a good rule of thumb. This sums up to about 1 hour and 20 minutes per problem, making it feasible to tackle three problems in a contest within four hours. Keep in mind that the time required may vary for easier and more challenging problems, especially in Platinum.
Thus, spending 45 minutes on finding the idea is a good time. However, bronze students should aim to bring their implementation time down to at most 30 minutes, especially for bronze problems which tend to have shorter implementations.
Tips for shortening implementation time
One way to achieve this is by organizing your code structure before you start coding. Have a clear idea of the sections, functions, and loops your code will include. This planning step can significantly reduce the time spent during implementation and debugging.
Additionally, if you find yourself stuck in debugging and your code is too long (e.g., over 40 lines for a bronze-level problem), consider simplifying sections of your code. Long, complex code is more prone to bugs. Condensing your code to less than 40 lines can often lead to the elimination of unidentifiable bugs. Higher-level competitors tend to code more concisely, so keeping your code clean and compact is a valuable skill.
Using a Debugger
Often, competitive programmers use simple print statements to debug their programs, and while this may be effective for shorter programs, as your code gets longer and longer, print statements can generate lots of confusion, slowing down the debugging process. To avoid losing time in this compartment, try using a debugger.
At its core, a debugger is a software tool designed to assist developers in finding and resolving bugs, glitches, and errors in their code. It provides a controlled environment where you can inspect the inner workings of your program, step through its execution line by line, and examine the values of variables at any given moment. While it might sound complex, debuggers are remarkably user-friendly and can drastically speed up the debugging process. For a comprehensive guide on how to use a debugger, check out Nathan’s video here.
Choosing Your Environment
For this tutorial, we'll be working with VSCode and Java. If you're using a different Integrated Development Environment (IDE) or text editor, the specifics might vary slightly, but the core functions remain the same. Debugging is all about understanding and controlling your code's execution.
Setting Breakpoints
Let's take a look at how to use a debugger effectively. We'll use a USACO Bronze problem from the 2020 February contest called "triangles" as an example. We won’t go into the specifics of the problem, so it’s fine if you aren’t familiar with it. Our goal is to understand how to use a debugger to ensure our code is running correctly.
A breakpoint is essentially a place in the code where we want to stop and check the current state of the variables, so we can see if any of the variables are not as we expected. We can set these breakpoints anywhere in the code. Then, when we debug, the debugger will run the program as normal, until it hits a breakpoint, when it then gives us full control.
Here, you can see that we define a breakpoint in line 15 by hovering to the left of the line number. In other IDEs, this may differ, but in general clicking around the line number will put a red dot, indicating a breakpoint.
The purpose of this breakpoint in line 15 is to check that the input has been properly read into our “points” array.
Once you’ve set breakpoints in all places where you want to check the state of the program, we can get to running the actual debugger.
Navigating the Debugger
To run the debugger in VS Code, simply go to the top right and click on the dropdown next to the run button, and select “Debug Java”.
If you cannot find this option in an IDE such as IntelliJ, try searching up how to run debug on your IDE.
Once you entered the debugger, your IDE will look something like this. It can be a bit overwhelming at first, but let’s explore everything that is going on.
Let's explore the debugger’s features:
Highlighted Current Line: Line 15 is highlighted, indicating the current execution point.
Variables Panel: This panel displays the values of all defined variables. For “triangles”, we can check if our points were read in correctly by expanding the "points" menu.
Hover to Inspect: You can hover over variables in your code to see their current values. For example, hover over "N" to see its value.
Skipping Ahead
Suppose we want to program to continue executing. We can use this menu found at the top of the IDE:
This menu allows us to step forward by clicking on the second icon from the left. Stepping forward means allowing the program to continue its very next line of code, which can be incredibly helpful, as we often want to see how our variables change as the program progresses.
If you’re stuck in a loop, and don’t want to continuously click the “step forward” button, we can skip ahead in the code to a specific point. Define another breakpoint at the line that you want to stop at, and use the “continue” button, which is the first icon from the left.
Exploring Functions
Suppose we are at a line of code where a function is being called. Clicking “step over” will simply go to the next line, not giving us any information about what is going on inside this function.
To read the state of the program inside the function as well, we can use the “step into” feature, which is the 3rd button from the left, when on a line of code that calls a function. Now, you can inspect the variables and calculations happening within that function as well. Similarly, to exit the function, we can use the “step out” feature, which is the 4th button from the left, which goes back to the code that called the function.
Watching Variables
Oftentimes, you will have tons and tons of variables, so keeping track of each one you are interested in can be really tedious. This is solved by another powerful tool: the watch panel, which can be found on the bottom left under the variables panel.
If you click the “+” on the top right of the panel, you can add a variable or expression that you are interested in keeping track of. For example, in the “triangles” problem, we can add “points[i]” to the watch panel, and the debugger will tell us the value of points at index i at every point in time. You can even keep track of a specific property, such as “points[i].x”.
Conditional Breakpoints
Suppose we have a long loop, and we don’t care about every iteration of the loop, just certain iterations. We can use a conditional breakpoint to set this up. To set up a conditional breakpoint, add a breakpoint normally, right click it, and “edit breakpoint”.
Now, we can enter an expression to define when we want this breakpoint to activate, allowing us to only pause the program when we want to.
That covers the essential functions of a debugger that you need to know. Debugging can be a bit overwhelming at first, but with practice, you'll become more efficient at identifying and fixing issues in your code.
Post-Contest Analysis
Content strategy extends its influence beyond the contest itself. After the contest concludes, it's time for a thorough post-contest analysis. This phase is where you consolidate your learning and identify areas for improvement. Post-contest review is much more time-effective for learning than spending your time doing another practice contest instead, as you’ll just make the same mistakes again.
Review your contest log and reflect on your performance. Ask yourself critical questions. Did you allocate too much time to a specific problem? Could I have gotten a problem with better time management? Post-contest analysis serves as a diagnostic tool, revealing your strengths and weaknesses. If you have a coach or mentor, have them review it too, as they can point out things that you might not have thought was a mistake.
The goal of post-contest analysis is not just to dwell on your mistakes but to learn from them. It's an opportunity to fine-tune your strategy for future contests. The insights gained during this phase are invaluable, paving the way for continuous improvement.
Continuous Improvement
The sign of a successful contestant is their commitment to continuous improvement. To foster this growth, implement changes based on your post-contest analysis.
I often witness remarkable score improvements in students who diligently work on their content strategy. Thus, make it a rule to assess your content strategy after each contest; even a five-minute review can lead to significant score enhancements.
Platinum-Specific Strategies
As you progress to the platinum level, the dynamics of content strategy evolve. As the goal shifts more towards one and a half problems, the importance of partial credits becomes even more apparent.
Embrace Partial Scoring
Within Platinum contests, partial credit becomes even more important, as they can substantially boost your overall score. Imagine achieving 75% on one problem, 25% on another, and 25% on the third, which leads to almost one and a half problems already! Since you're not aiming for full solutions as often, allocate more time to partials. This approach can lead to a higher overall score, even if you don't complete any problems.
However, still shoot for the stars; whenever you can, aim for full solves. With proper preparation, you may find full solutions when thinking about how to solve the entire problem, or even if you don’t, you’ll have already found partial solutions without even knowing it.
Strategic Time Allocation
As always, managing time wisely is critical in all divisions, but it is especially important in Platinum, as you also have to balance going for full solves with going for partials. Begin with any problems that you might have the full idea for. Then, as you are nearing the end of the contest, focus on partials, balancing your time among the remaining problems. Time is a precious resource, especially in platinum contests, and should be allocated strategically.
Conclusion
As the upcoming USACO season approaches, remember that content strategy is your secret weapon. It can turn "I could have gotten that if I just had more time" into "I got it because I had a solid content strategy."
Maintain a contest log, organize code before implementing, use a debugger, embrace task switching, read all problems, and conduct post-contest analyses. These steps will significantly enhance your performance. For platinum participants, focus on partial scoring and strategic time allocation to maximize your points.
So, as you prepare for the upcoming contest, make content strategy and faster implementation/debugging a central part of your preparation. It's not just about coding faster but also about coding smarter. Effective content strategy can make all the difference in your journey to USACO success.
Thank you for reading, and best of luck in your USACO journey! May your contest log be your guiding star toward victory.