Solve day 1, add template

01/src/main.c

@@ -0,0 +1,167 @@
+#include <stdbool.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+struct elf {
+  int size;
+  int *calories;
+};
+
+int get_num_of_elves(const char *fileName) {
+  char line[300];
+  int emptyLine = 0;
+  FILE *fp = fopen(fileName, "r");
+  if (fp == NULL) {
+    printf("Error: Could not open specified file!\n");
+    return -1;
+  } else {
+    while (fgets(line, 300, fp)) {
+      int i = 0;
+      int len = strlen(line);
+      emptyLine++;
+      for (i = 0; i < len; i++) {
+        if (line[i] != '\n' && line[i] != '\t' && line[i] != ' ') {
+          emptyLine--;
+          break;
+        }
+      }
+    }
+    fclose(fp);
+    return ++emptyLine;
+  }
+}
+
+void load_data(int num_of_elves, char *filename, struct elf **arr) {
+  FILE *fp = fopen(filename, "r");
+  if (fp == NULL) {
+    printf("Error: Could not open specified file!\n");
+    return;
+  }
+  for (int i = 0; i < num_of_elves; i++) {
+    // Count number of lines until blank line
+    int num_of_lines = 0;
+    char line[300];
+    int char_count = 0;
+    while (fgets(line, 300, fp)) {
+      int i = 0;
+      int len = strlen(line);
+      char_count += len;
+      for (i = 0; i < len; i++) {
+        if (line[i] != '\n' && line[i] != '\t' && line[i] != ' ') {
+          num_of_lines++;
+          break;
+        }
+      }
+      if (line[0] == '\n') {
+        break;
+      }
+    }
+    // Check for blank line at EOF
+    if(line[0] == EOF) {
+      break;
+    }
+
+    if (num_of_lines == 0) {
+      i--;
+      continue;
+    }
+
+    // Go back to start of current elf's data
+    fseek(fp, -char_count, SEEK_CUR);
+
+    struct elf *data = *arr;
+    // Allocate memory for array
+    data[i].size = num_of_lines;
+    data[i].calories = malloc(num_of_lines * sizeof(int));
+
+    // Load the data
+    for (int j = 0; j < num_of_lines; j++) {
+      int res = fscanf(fp, "%d", &data[i].calories[j]);
+      if (res != 1){
+        printf("Error, bad file format!");
+        return;
+      }
+    }
+  }
+  fclose(fp);
+}
+
+void count_elf_calories(struct elf **arr, int num_of_elves){
+  struct elf *data = *arr;
+  for (int i = 0; i < num_of_elves; i++){
+    int sum = 0;
+    for (int j = 0; j < data[i].size; j++){
+      sum += data[i].calories[j];
+      data[i].calories[j] = 0;
+    }
+    data[i].calories[0] = sum;
+  }
+}
+
+char *argv_parser(int argc, char *argv[]) {
+  if (argc != 2) {
+    fprintf(stderr, "Usage: %s <filename>\n", argv[0]);
+    return NULL;
+  }
+  return argv[1];
+}
+
+int main(int argc, char *argv[]) {
+  struct elf *arr;
+  char *filename = argv_parser(argc, argv);
+
+  if (filename == NULL) {
+    return 1;
+  }
+
+  int num_of_elves = get_num_of_elves(filename);
+  if (num_of_elves == -1) {
+    return 1;
+  }
+
+  arr = malloc(num_of_elves * sizeof(struct elf));
+
+  load_data(num_of_elves, filename, &arr);
+
+  count_elf_calories(&arr, num_of_elves);
+
+  // Print 3 elfs carrying the most calories
+  int first_elf_cal = 0;
+  int first_elf_idx = 0;
+  int second_elf_cal = 0;
+  int second_elf_idx = 0;
+  int third_elf_cal = 0;
+  int third_elf_idx = 0;
+  for (int i = 0; i < num_of_elves; i++){
+    if (arr[i].calories[0] > first_elf_cal){
+      third_elf_cal = second_elf_cal;
+      third_elf_idx = second_elf_idx;
+      second_elf_cal = first_elf_cal;
+      second_elf_idx = first_elf_idx;
+      first_elf_cal = arr[i].calories[0];
+      first_elf_idx = i;
+    } else if (arr[i].calories[0] > second_elf_cal){
+      third_elf_cal = second_elf_cal;
+      third_elf_idx = second_elf_idx;
+      second_elf_cal = arr[i].calories[0];
+      second_elf_idx = i;
+    } else if (arr[i].calories[0] > third_elf_cal){
+      third_elf_cal = arr[i].calories[0];
+      third_elf_idx = i;
+    }
+  }
+  printf("Elf %d carries the most calories at %d calories\n", first_elf_idx, first_elf_cal);
+  printf("Elf %d carries the second most calories at %d calories\n", second_elf_idx, second_elf_cal);
+  printf("Elf %d carries the third most calories at %d calories\n", third_elf_idx, third_elf_cal);
+
+  // Print the top 3 elves with the most calories
+  printf("The top 3 elves carry %d calories\n", first_elf_cal + second_elf_cal + third_elf_cal);
+
+  // Free memory
+  for (int i = 0; i < num_of_elves; i++){
+    free(arr[i].calories);
+  }
+  free(arr);
+  return 0;
+}