refactor various files

S1/GdCP/uebung/a03.c

@@ -0,0 +1,28 @@
+typedef struct interval_s {
+  long low;  // lower bound 
+  long up;   // upper bound
+} interval_t;
+
+long max(long a, long b) {
+  if (a > b) return a;
+  return b;
+}
+
+long min(long a, long b) {
+  if (a > b) return b;
+  return a;
+}
+
+int is_empty(const interval_t *a) {
+  return a->low > a-> up;
+}
+
+int is_empty_intersection(const struct interval_s *a, const struct interval_s *b) {
+  if (!a || !b) return 1;
+  const interval_t *l[] = {a, b};
+  for (int i = 0; i < 2; i++) {
+    if (is_empty(l[i])) return 1;
+  }
+  interval_t s = {max(a->low, b->low), min(a->up, b->up)};
+  return is_empty(&s);
+};