Coursera - Computer Science: Programming With A Purpose

Week 1: Hello, World - Integers And Booleans

Jul 1, 2020

Write a program RightTriangle that takes three integer command-line arguments and determines whether they constitute the side lengths of some right triangle.

The following two conditions are necessary and sufficient:

Each integer must be positive.
The sum of the squares of two of the integers must equal the square of the third integer.

~/Desktop/hello> javac RightTriangle.java

~/Desktop/hello> java RightTriangle 3 4 5
true

~/Desktop/hello> java RightTriangle 13 12 5
true

~/Desktop/hello> java RightTriangle 1 2 3
false

~/Desktop/hello> java RightTriangle -3 4 -5
false

Note: the above description is copied from Coursera and converted to markdown for convenience

Solution:

public class RightTriangle {

    public static void main(String[] args) {
        // use long instead of int to handle overflow
        final long a = Long.parseLong(args[0]);
        final long b = Long.parseLong(args[1]);
        final long c = Long.parseLong(args[2]);

        final long a2 = a * a;
        final long b2 = b * b;
        final long c2 = c * c;

        final boolean result = (a > 0) && (b > 0) && (c > 0)
                && ((a2 + b2 == c2) || (a2 + c2 == b2) || (b2 + c2 == a2));
        System.out.println(result);
    }
}

Link To: Java Source Code