wronganswer

Haxe library for competitive programming (mainly intended for AtCoder).

Requires Haxe 4.

Target platforms

Supports following targets with the same API:

• Java
• JavaScript
• Eval

Features

• Standard input (wa.CharIn, wa.CharIns, wa.naive.CharIn, wa.naive.CharIns)
• Standard output (wa.CharOut, wa.CharOuts)
• Utility static functions (wa.Ints, wa.Strs, wa.Floats, wa.Vecs)
• Abstracted primitives (wa.Char16, wa.Char32, wa.Bits)
• String buffer (wa.StrBuf, wa.StrBufs)
• Other (wa.Printer, wa.Whitespace)
• Debug logger (wa.Debug)
• Command for bundling wronganswer modules via import statements (bundle)
• (More to be added. Maybe.)

Note: The package name is wa, not the same as the library name wronganswer.

Caveats

Super unstable!

Usage > CharIn/CharOut

These provide optimized standard I/O.

CharOut works as a string buffer (on java target, it's based on PrintWriter).
At the end of the program you have to call print()/println() explicitly.

import wa.CharIn;
import wa.CharOut;

class Main {
	static function main() {
		final inputBufferCapacity = 32;
		final cin = new CharIn(inputBufferCapacity);

		final strVal = cin.str(); // Reads until next whitespace
		final intVal = cin.int(); // Ditto + casts to Int
		final strVal2 = cin.until(LF); // Reads until next LF

		final cout = new CharOut();

		cout.str(strVal); // Appends `String` to the buffer
		cout.space(); // Appends a space
		cout.int(intVal); // Appends `Int`
		cout.lf(); // Appends LF
		cout.print(); // Prints buffered data
		// CharOut methods can also be chained.
	}
}

Read all at once

On js target, sequential loading can lead to performance problems.
So you might also want to read all data at once:

import wa.CharIn;
using wa.CharIns; // for all() and other additional methods

class Main {
	static function main() {
		final inputBufferCapacity = 65536;
		final cin = new CharIn(inputBufferCapacity);

		final data:String = cin.all();
		final lines:Array<String> = data.split("\n");

		// ...
	}
}

Usage > naive CharIn

You can also use a minimal (but not quite optimized) implementation of CharIn to reduce code to be appended when you submit.

import wa.naive.CharIn;

class Main {
	static function main() {
		final cin = new CharIn();

		final strVal = cin.str(); // Reads until next whiespace
		final intVal = cin.int(); // Ditto

		Sys.println('$strVal $intVal');
	}
}

Usage > bundle command

In order to submit your code to a contest, you might have to bundle it to a single file i.e. remove import statements (e.g. import wa.CharIn;) and append the actual implementation instead.

This can be automatically done with the command below:

haxelib run wronganswer bundle [full path of your hx file] [target (java/js/eval)]

Example

haxelib run wronganswer bundle C:/yourDirectory/Main.hx java

In the same directory the above creates a new file Main.bundle.hx which includes code of wronganswer for Java target.

And you might also want to do more automation, such as:

:: bundle.bat (should be placed in the same directory. For Windows only!)
haxelib run wronganswer bundle %~dp0Main.hx java
clip < %~dp0Main.bundle.hx

Help

haxelib run wronganswer bundle help

The above will display a list of import/using statements that can be resolved.

Notes

• As you can see by the help command, bundle works only with module-level imports of wronganswer modules.
  Also avoid using wronganswer features without importing (e.g. new wa.CharIn(16)), which cannot be resolved.
• Pay attension to the shadowing of functions (especially if you have using) which can lead to inconsistent behavior before/after bundling.
• bundle cannot ignore import/using in multiline comments (/* ... */).
  Use singleline comment (// ...) for commenting them out.
• Make sure that the emitted code is working properly before submitting it!
  If not, um, good luck.