Create QuadraticEquationSolver.java

equationsolver/QuadraticEquationSolver.java

@@ -0,0 +1,61 @@
+package equationsolver;
+
+import java.util.Random;
+
+public final class QuadraticEquationSolver {
+    private double a;
+    private double b;
+    private double c;
+    private double x[];
+
+    public QuadraticEquationSolver(double a, double b, double c) {
+        if (a == 0)
+            throw new IllegalArgumentException("The coefficient of the quadratic term cannot be zero.");
+        double discriminant = b * b - 4 * a * c;
+        if (discriminant < 0)
+            throw new IllegalArgumentException("The quadratic equation has no real roots.");
+        this.a = a;
+        this.b = b;
+        this.c = c;
+        this.x = new double[2];
+        double sqrtDiscriminant = Math.sqrt(discriminant);
+        x[0] = (-b - sqrtDiscriminant) / (2 * a);
+        x[1] = (-b + sqrtDiscriminant) / (2 * a);
+    }
+
+    public double getA() {
+        return a;
+    }
+
+    public double getB() {
+        return b;
+    }
+
+    public double getC() {
+        return c;
+    }
+
+    public double[] getX() {
+        return x;
+    }
+
+    public static void main(String[] args) {
+        Random r = new Random();
+        double a = r.nextInt(3) == 0 ? 0 : r.nextDouble(200) - 100;
+        double b = r.nextDouble(200) - 100;
+        double c = r.nextDouble(200) - 100;
+        String equation = String.format("%sx^2 %s %sx %s %s = 0;",
+                a < 0 ? "-" + -a : a,
+                b < 0 ? "-" : "+",
+                b < 0 ? -b : b,
+                c < 0 ? "-" : "+",
+                c < 0 ? -c : c);
+        System.out.println(equation);
+        try {
+            QuadraticEquationSolver solver = new QuadraticEquationSolver(a, b, c);
+            System.out.println("x = " + solver.getX()[0] + ", " + solver.getX()[1] + ".");
+        } catch (IllegalArgumentException e) {
+            System.err.println(e);
+        }
+    }
+}