advent-of-c-ode/day2/day2.c

#include <ctype.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "../libs/buffered_reader.h"
#include "../libs/data_structures.h"

#define MAX_RED 12
#define MAX_GREEN 13
#define MAX_BLUE 14

int decodea(char *str);
int decodeb(char *str);
int get_color(const char *str);
bool validate_round(char *str, int dice[]);
// SEPARATORS
const char *GAME_SEP = ":";
const char *COLOR_SEP = ",";
const char *ROUND_SEP = ";";
// COLOR
const char *RED = "red";
const char *GREEN = "green";
const char *BLUE = "blue";

list *stack;

enum Color { Red = 0, Green = 1, Blue = 2 };

int main(int argc, char *argv[]) {
  if (argc < 3) {
    printf("usage: day2 INPUT_FILE a|b\n");
    exit(1);
  }

  char part = *argv[2];

  filelines *lines = flines(argv[1]);

  if (lines == NULL) {
    printf("Failed to read file");
    exit(1);
  }

  // init stack
  initList(&stack);

  int sum = 0;
  for (int i = 0; i < lines->size; i++) {
    int d = 0;
	//based on cli input change function
    switch (part) {
    case 'a':
      d = decodea(get(lines, i));
      break;
    case 'b':
      d = decodeb(get(lines, i));
      break;
    }

	/*
    if (d == 0) {
      printf("^^^^ Game %d ^^^^^\n", i + 1);
    } else {
      printf("---- Game %d -----\n", i + 1);
    }
	*/

    sum += d;
  }
	printf("Sum: %d\n", sum);
}

int decodea(char *str) {
  // find semicolon
  int game_split = strcspn(str, GAME_SEP);
  char *game_str = str + game_split + 1;
  if (!*game_str || str == game_str) {
    printf("Could not find game separator.\n");
    exit(1);
  }

  // parse colors
  char *token;
  token = strtok(game_str, ";");

  filelines *rounds;
  initFileLines(&rounds);

  // Get rounds
  while (token) {
    insert(rounds, token);
    token = strtok(NULL, ";");
  }

  // validate rounds
  for (int i = 0; i < rounds->size; i++) {
    int dice[] = {0, 0, 0};
    if (!validate_round(get(rounds, i), dice)) {
      return 0;
    }
  }

  freeLines(rounds);
  clears(stack);
  int space_index = strcspn(str, " ");
  for (int i = space_index + 1; i < game_split; i++) {
    pushs(stack, *(str + i));
  }

  return atoi(contents(stack));
}

int decodeb(char *str) {
  // find semicolon
  int game_split = strcspn(str, GAME_SEP);
  char *game_str = str + game_split + 1;
  if (!*game_str || str == game_str) {
    printf("Could not find game separator.\n");
    exit(1);
  }

  // parse colors
  char *token;
  token = strtok(game_str, ";");

  filelines *rounds;
  initFileLines(&rounds);

  // Get rounds
  while (token) {
    insert(rounds, token);
    token = strtok(NULL, ";");
  }

  int min[] = {0,0,0};
  // validate rounds
  for (int i = 0; i < rounds->size; i++) {
    int dice[] = {0, 0, 0};
    validate_round(get(rounds, i), dice);
	min[Red] = dice[Red] >= min[Red] ? dice[Red] : min[Red];
	min[Green] = dice[Green] >= min[Green] ? dice[Green] : min[Green];
	min[Blue] = dice[Blue] >= min[Blue] ? dice[Blue] : min[Blue];
  }

  return min[Red] * min[Green] * min[Blue];
}

int get_color(const char *str) {
  if (strstr(str, RED)) {
    return Red;
  }
  if (strstr(str, GREEN)) {
    return Green;
  }
  if (strstr(str, BLUE)) {
    return Blue;
  }
  return -1;
}

bool validate_round(char *str, int dice[]) {
  list *color_list;
  initList(&color_list);

  char *token;
  token = strtok(str, ",");

  while (token) {
    // trim leading whitespace
    while (isspace(*token))
      token++;

    // printf("%s,", token);
    // actually do the stuff
    clears(color_list);
    char *c = token;
    while (c) {
      if (isspace(*c)) {
        break;
      }
      pushs(color_list, *c);
      c++;
    }
    enum Color color = get_color(token);
    dice[color] += atoi(contents(color_list));

    token = strtok(NULL, ",");
  }
  // printf("\n");

  freelist(color_list);

  return dice[Red] <= MAX_RED && dice[Green] <= MAX_GREEN &&
         dice[Blue] <= MAX_BLUE;
}