Exercise 5 draft

Added Exercise 5 but incomplete

Informatik_I/Exercise_5/Task_2/functions.cpp

@@ -0,0 +1,38 @@
+// PRE:  x > 0
+// POST: returns n^x
+int f1(int n, int x) {
+  int res = 1;
+  for (; x > 0; x--) {
+    res *= n;
+  }
+  return res;
+}
+
+// PRE:  n > 0
+// POST: returns number of devisions by 10 with n
+int f2(int n) {
+  int i = 0;
+  while (n > 0) {
+    n = n / 10;
+    ++i;
+  }
+  return i;
+}
+
+// PRE:  n > 1
+// POST: returns a bool to determine if n is prime
+bool f3(int n) {
+  int i = 2;
+  for (; n % i != 0; ++i);
+  return n == i;
+}
+
+// PRE:  n is square number
+// POST: returns root of n
+int f4(int n) {
+  int i = 0;
+  while (i * i != n) {
+    ++i;
+  }
+  return i;
+}