Add a read-line-by-line function

c/2022/1/problem.c

@@ -5,28 +5,16 @@
 #include "../../lib/aoc.h"
 
 int main() {
-  char *input = aoc_read_input();
-  char *seek = input;
-
   int current_cals = 0;
   int current_elf = 0;
   int max_elf = 0;
   int second_max_elf = 0;
   int third_max_elf = 0;
 
-  while (seek != NULL) {
-    char *double_line_break = strstr(seek, "\n\n");
-    if (double_line_break == NULL) {
-      seek = NULL;
-    } else {
-      *double_line_break = '\0';
-      char *line = strtok(seek, "\n");
-      while (line != NULL) {
-	current_cals = atoi(line);
-	current_elf += current_cals;
-	line = strtok(NULL, "\n");
-      }
+  char *line;
 
+  while ((line = aoc_read_line()) != NULL) {
+    if (strlen(line) == 0) {
       if (current_elf > max_elf) {
 	int z = current_elf;
 	current_elf = max_elf;
@@ -46,16 +34,15 @@ int main() {
       }
 
       current_elf = 0;
-      
-      seek = double_line_break + 1;
-      *seek = '\0';
-      seek = seek + 1;
+    } else {
+      current_cals = atoi(line);
+      current_elf += current_cals;
     }
   }
 
   printf("Part 1: %d\n", max_elf);
   printf("Part 2: %d\n", max_elf + second_max_elf + third_max_elf);
 
-  free(input);
+  aoc_free();
   return 0;
 }

c/lib/aoc.h

@@ -4,9 +4,11 @@
 
 #define INITIAL_BUFFER_SIZE 2
 
+char *input_buffer;
+
 char *aoc_read_input(void) {
   int buffer_size = INITIAL_BUFFER_SIZE;
-  char *input_buffer = malloc(buffer_size);
+  input_buffer = malloc(buffer_size);
   int chars_read = read(STDIN_FILENO, input_buffer, buffer_size);
   char *buffer_position = &input_buffer[chars_read];
 
@@ -20,3 +22,23 @@ char *aoc_read_input(void) {
   input_buffer[chars_read] = 0;
   return input_buffer;
 }
+
+char *seek = NULL;
+
+char *aoc_read_line(void) {
+  if (input_buffer == NULL) aoc_read_input();
+
+  if (seek == NULL) seek = input_buffer;
+
+  char *line_break = strstr(seek, "\n");
+  if (line_break == NULL) return NULL;
+
+  *line_break = '\0';
+  char *token = seek;
+  seek = line_break + 1;
+  return token;
+}
+
+void aoc_free(void) {
+  free(input_buffer);
+}