restructure and add ipi texs

ws2019/ipi/uebungen/cpp_headers/Rational.cc

@@ -0,0 +1,59 @@
+int Rational::numerator () {
+  return n;
+}
+
+int Rational::denominator () {
+  return d;
+}
+
+void Rational::print () {
+  ::print(n,"/",d,0);
+}
+
+// ggT zum kuerzen
+int Rational::ggT (int a, int b) {
+  return (b==0) ? a : ggT(b,a%b);
+}
+
+// Konstruktoren
+Rational::Rational (int num, int denom)
+{
+  int t = ggT(num,denom);
+  if (t!=0)
+    {
+      n=num/t;
+      d=denom/t;
+    }
+  else
+    {
+      n = num;
+      d = denom;
+    }
+}
+
+Rational::Rational (int num) {
+  n=num;
+  d=1;
+}
+
+Rational::Rational () {
+  n=0;
+  d=1;
+}
+
+// Operatoren
+Rational Rational::operator+ (Rational q) {
+  return Rational(n*q.d+q.n*d,d*q.d);
+}
+
+Rational Rational::operator- (Rational q) {
+  return Rational(n*q.d-q.n*d, d*q.d);
+}
+
+Rational Rational::operator* (Rational q) {
+  return Rational(n*q.n, d*q.d);
+}
+
+Rational Rational::operator/ (Rational q) {
+  return Rational(n*q.d,d*q.n);
+}