updated eddington.c

c/eddington.c

@@ -18,15 +18,52 @@ void usage(char *prog) {
   );
 }
 
-int main(int argc, char *argv[])
-{
-
-  FILE *file = stdin;
-  int is_stdin = 1;
+/** Read lines from file stream and return them as an integer array
+ *
+ *  @param[in] file the file stream to read from
+ *  @param[out] n will be written with the number of values read in
+ */
+int *read_values(FILE *file, int *n) {
   char line[MAX_LEN];
   int len = 1024;
-  int n, c, opt;
   int *r = malloc(len * sizeof(int));
+  while (fgets(line, MAX_LEN, file) != NULL) {
+    if (*n >= len) {
+      len *= 2;
+      r = realloc(r, len * sizeof(int));
+    }
+    r[(*n)++] = atoi(line);
+  }
+  return r;
+}
+
+/** Compute the eddington number of an integer array and print the results
+ *
+ *  @param[in] r the integer array to compute the Eddington number on
+ *  @param[in] n the length of \p r
+ *  @param[in] c whether to print the cumulative result
+ */
+void compute_eddington_number(int *r, int n, int c) {
+  int *h = calloc(n + 1, sizeof(int));
+
+  int E = 0;
+  for (int i=0, above=0; i < n; i++) {
+    if (r[i] > E) {
+      if (r[i] < n) h[r[i]]++;
+      if (++above > E) above -= h[++E];
+    }
+
+    if (c) /* Cumulative print */
+      printf("%d\n", E);
+  }
+
+  if (!c) /* Summary print if no cumulative */
+    printf("%d\n", E);
+}
+
+int main(int argc, char *argv[]) {
+  int *r;
+  int n, c, opt;
 
   n = c = opt = 0;
 
@@ -50,41 +87,18 @@ int main(int argc, char *argv[])
     }
 
   if (optind < argc && strncmp(argv[optind], "-", 1)) {
-    is_stdin = 0;
+    FILE *file;
     if ((file = fopen(argv[optind], "r")) == NULL) {
       fprintf(stderr, "Could not open file %s\n", argv[optind]);
       return EXIT_FAILURE;
     }
+    r = read_values(file, &n);
+    fclose(file);
+  } else {
+    r = read_values(stdin, &n);
   }
 
-  // Read in file
-  while (fgets(line, MAX_LEN, file) != NULL) {
-    if (n >= len) {
-      len *= 2;
-      r = realloc(r, len * sizeof(int));
-    }
-    r[n++] = atoi(line);
-  }
-
-  if (!is_stdin) fclose(file);
-
-  // Initialize histogram
-  int *h = calloc(n + 1, sizeof(int));
-
-  // Run the algorithm
-  int E = 0;
-  for (int i=0, above=0; i < n; i++) {
-    if (r[i] > E) {
-      if (r[i] < n) h[r[i]]++;
-      if (++above > E) above -= h[++E];
-    }
-
-    if (c) /* Cumulative print */
-      printf("%d\n", E);
-  }
-
-  if (!c) /* Summary print if no cumulative */
-    printf("%d\n", E);
+  compute_eddington_number(r, n, c);
 
   return EXIT_SUCCESS;
 }