Pythagorean triples: Difference between revisions

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=={{header|Java}}==

[[Category:Arbitrary precision]]Theoretically, this can go "forever", but it takes a while, so only the minimum is shown. Luckily, <code>BigInteger</code> has a GCD method built in.

<lang java>~~import java.math.BigInteger;~~

import java.math.BigInteger;

import static java.math.BigInteger.ONE;

public class PythTrip{

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public static void main(String[] args){

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long tripCount = 0, primCount = 0;

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public static void main(String[] args){

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//change this to whatever perimeter limit you want;the RAM's the limit

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long tripCount = 0, primCount = 0;

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BigInteger periLimit = new BigInteger("~~100~~");

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//change this to whatever perimeter limit you want;the RAM's the limit

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for(BigInteger a = BigInteger.ONE;

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BigInteger periLimit = new BigInteger("10000"),

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a.compareTo(~~periLimit~~) < 0; a = a.add(~~BigInteger.~~ONE)){

peri2 = periLimit.divide(new BigInteger("2")),

peri3 = periLimit.divide(new BigInteger("3"));

for(BigInteger b = ~~new~~ ~~BigInteger~~(a.~~toString~~());

for(BigInteger a = ONE; a.compareTo(peri3) < 0; a = a.add(ONE)){

BigInteger aa = a.multiply(a);

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b.compareTo(~~periLimit~~) < 0; b = b.add(~~BigInteger.~~ONE)){

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for(BigInteger b = new BigInteger(a.toString()).add(ONE);

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b.compareTo(peri2) < 0; b = b.add(ONE)){

BigInteger bb = b.multiply(b);

BigInteger ab = a.add(b);

BigInteger aabb = aa.add(bb);

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for(BigInteger c = new BigInteger(b.toString()).add(ONE);

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c.compareTo(peri2) < 0; c = c.add(ONE)){

int compare = aabb.compareTo(c.multiply(c));

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for(BigInteger c = new BigInteger(b.toString());

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//if a+b+c > periLimit

c.compareTo(periLimit) < 0; c = c.add(BigInteger.ONE)){

if(ab.add(c).compareTo(periLimit) > 0){

break;

}

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//if a^2 + b^2 != c^2

if(compare < 0){

break;

}else if (compare == 0){

tripCount++;

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System.out.print(a + ", " + b + ", " + c);

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//does binary GCD under the hood

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//if a+b+c > periLimit

if(a.~~add~~(b~~).add(c~~).compareTo(~~periLimit~~) > 0)~~break;~~

if(a.gcd(b).compareTo(ONE) == 0){

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System.out.print(" primitive");

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//if a^2 + b^2 != c^2

primCount++;

if(a.pow(2).add(b.pow(2)).compareTo(c.pow(2)) != 0)

}

continue;

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System.out.println();

}

tripCount++;

}

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System.out.print(a +", "+b+", "+c);

}

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//does binary GCD under the hood

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System.out.println("Up to a perimeter of " + periLimit + ", there are "

if(a.gcd(b).compareTo(BigInteger.ONE) == 0){

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+ tripCount + " triples, of which " + primCount + " are primitive.");

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System.out.print(" primitive");

}

primCount++;

}

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System.out.println();

}

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System.out.println("Up to a perimeter of "+periLimit+", there are "+

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tripCount+" triples, of which "+primCount+" are primitive.");

}

}</lang>

Output: