Java 15 was released a few days ago. Here are some changes that may be useful for competitive programming.

• Pattern matching for instanceof, first introduced in Java 14, is still a preview.
• Text blocks, first introduced in Java 13, are now final:

String input = """
	3 3
	1 2
	1 3
	2 3""";

• Records, first introduced in Java 14, are now final:

record Fraction(int num, int den) {
	Fraction {
		if (den == 0) {
			throw new IllegalArgumentException("zero denominator");
		}
		if (den < 0) {
			num = -num;
			den = -den;
		}
	}

	Fraction add(Fraction o) {
		return new Fraction(num * o.den + den * o.num, den * o.den);
	}

	// ...
}

• Useful new methods: CharSequence.isEmpty() (also inherited by String), String.stripIndent() (useful for text blocks), String.formatted(), Math.absExact().

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