refactor various files

S1/GdCP/uebung/aoc18.c

@@ -0,0 +1,31 @@
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+void mix(long *n, long r) { *n = *n ^ r; }
+void prune(long *n) { *n = *n % 16777216; }
+
+int main() {
+  FILE *file = fopen("18.in", "r");
+  if (!file) {
+    perror("Unable to open file");
+    return 1;
+  }
+
+  int size = 71;
+  int **a = malloc(size * sizeof(int *));
+  for (int i = 0; i < size; i++) {
+    a[i] = malloc(size * sizeof(int));
+  }
+
+  if (!a) {
+    perror("Memory allocation failed");
+    fclose(file);
+    return 1;
+  }
+
+  fclose(file);
+
+  free(a);
+  return 0;
+}