Initial data commit

Task/Arithmetic-Complex/Java/arithmetic-complex.java

@@ -0,0 +1,52 @@
+public class Complex {
+    public final double real;
+    public final double imag;
+
+    public Complex() {
+        this(0, 0);
+    }
+
+    public Complex(double r, double i) {
+        real = r;
+        imag = i;
+    }
+
+    public Complex add(Complex b) {
+        return new Complex(this.real + b.real, this.imag + b.imag);
+    }
+
+    public Complex mult(Complex b) {
+        // FOIL of (a+bi)(c+di) with i*i = -1
+        return new Complex(this.real * b.real - this.imag * b.imag,
+                this.real * b.imag + this.imag * b.real);
+    }
+
+    public Complex inv() {
+        // 1/(a+bi) * (a-bi)/(a-bi) = 1/(a+bi) but it's more workable
+        double denom = real * real + imag * imag;
+        return new Complex(real / denom, -imag / denom);
+    }
+
+    public Complex neg() {
+        return new Complex(-real, -imag);
+    }
+
+    public Complex conj() {
+        return new Complex(real, -imag);
+    }
+
+    @Override
+    public String toString() {
+        return real + " + " + imag + " * i";
+    }
+
+    public static void main(String[] args) {
+        Complex a = new Complex(Math.PI, -5); //just some numbers
+        Complex b = new Complex(-1, 2.5);
+        System.out.println(a.neg());
+        System.out.println(a.add(b));
+        System.out.println(a.inv());
+        System.out.println(a.mult(b));
+        System.out.println(a.conj());
+    }
+}