Skip to content

refactor: improve PythagoreanTriple logic and add parameterized tests #6350

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Jul 7, 2025
Merged

refactor: improve PythagoreanTriple logic and add parameterized tests #6350

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
903d4cb
refactor: improve PythagoreanTriple logic and add parameterized tests
alxkm Jul 7, 2025
ccf39ef
refactor: fix clang format issues
alxkm Jul 7, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
45 changes: 26 additions & 19 deletions src/main/java/com/thealgorithms/maths/PythagoreanTriple.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,36 +1,43 @@
package com.thealgorithms.maths;

/**
* https://en.wikipedia.org/wiki/Pythagorean_triple
* Utility class to check if three integers form a Pythagorean triple.
* A Pythagorean triple consists of three positive integers a, b, and c,
* such that a² + b² = c².
*
* Common examples:
* - (3, 4, 5)
* - (5, 12, 13)
*
* Reference: https://en.wikipedia.org/wiki/Pythagorean_triple
*/
public final class PythagoreanTriple {
private PythagoreanTriple() {
}

public static void main(String[] args) {
assert isPythagTriple(3, 4, 5);
assert isPythagTriple(5, 12, 13);
assert isPythagTriple(6, 8, 10);
assert !isPythagTriple(10, 20, 30);
assert !isPythagTriple(6, 8, 100);
assert !isPythagTriple(-1, -1, 1);
private PythagoreanTriple() {
}

/**
* Check if a,b,c are a Pythagorean Triple
* Checks whether three integers form a Pythagorean triple.
* The order of parameters does not matter.
*
* @param a x/y component length of a right triangle
* @param b y/x component length of a right triangle
* @param c hypotenuse length of a right triangle
* @return boolean <tt>true</tt> if a, b, c satisfy the Pythagorean theorem,
* otherwise
* <tt>false</tt>
* @param a one side length
* @param b another side length
* @param c another side length
* @return {@code true} if (a, b, c) can form a Pythagorean triple, otherwise {@code false}
*/
public static boolean isPythagTriple(int a, int b, int c) {
if (a <= 0 || b <= 0 || c <= 0) {
return false;
} else {
return (a * a) + (b * b) == (c * c);
}

// Sort the sides so the largest is treated as hypotenuse
int[] sides = {a, b, c};
java.util.Arrays.sort(sides);

int x = sides[0];
int y = sides[1];
int hypotenuse = sides[2];

return x * x + y * y == hypotenuse * hypotenuse;
}
}
24 changes: 13 additions & 11 deletions src/test/java/com/thealgorithms/maths/PythagoreanTripleTest.java
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,22 +1,24 @@
package com.thealgorithms.maths;

import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertEquals;
import static org.junit.jupiter.api.Assertions.assertTrue;

import org.junit.jupiter.api.Test;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.CsvSource;

public class PythagoreanTripleTest {

@ParameterizedTest
@CsvSource({"3, 4, 5, true", "6, 8, 10, true", "9, 12, 15, true", "12, 16, 20, true", "15, 20, 25, true", "18, 24, 30, true", "5, 20, 30, false", "6, 8, 100, false", "-2, -2, 2, false", "0, 0, 0, false", "5, 5, 5, false"})
void testIsPythagoreanTriple(int a, int b, int c, boolean expected) {
assertEquals(expected, PythagoreanTriple.isPythagTriple(a, b, c));
}

@Test
public void testPythagoreanTriple() {
assertTrue(PythagoreanTriple.isPythagTriple(3, 4, 5));
assertTrue(PythagoreanTriple.isPythagTriple(6, 8, 10));
assertTrue(PythagoreanTriple.isPythagTriple(9, 12, 15));
assertTrue(PythagoreanTriple.isPythagTriple(12, 16, 20));
assertTrue(PythagoreanTriple.isPythagTriple(15, 20, 25));
assertTrue(PythagoreanTriple.isPythagTriple(18, 24, 30));
assertFalse(PythagoreanTriple.isPythagTriple(5, 20, 30));
assertFalse(PythagoreanTriple.isPythagTriple(6, 8, 100));
assertFalse(PythagoreanTriple.isPythagTriple(-2, -2, 2));
void testUnorderedInputStillValid() {
// Should still detect Pythagorean triples regardless of argument order
assertTrue(PythagoreanTriple.isPythagTriple(5, 3, 4));
assertTrue(PythagoreanTriple.isPythagTriple(13, 12, 5));
}
}
Loading