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

#include "../../lib/aoc.h"

typedef struct Ratio {
  long long num;
  long long denom;
} Ratio;

typedef struct Line {
  Ratio slope;
  Ratio offset;
} Line;

Ratio ratio_subtract(Ratio r1, Ratio r2) {
  Ratio r3;
  r3.num= r1.num * r2.denom - r2.num * r1.denom;
  r3.denom= r1.denom* r2.denom;
  return r3;
}

Ratio ratio_divide(Ratio r1, Ratio r2) {
  Ratio r3;
  r3.num = r1.num * r2.denom;
  r3.denom = r1.denom * r2.num;
  return r3;
}

bool proper(Ratio r) {
  return r.num % r.denom == 0;
}

Ratio intersect_x(Line l1, Line l2) {
  Ratio left_side = ratio_subtract(l1.slope, l2.slope);
  Ratio right_side = ratio_subtract(l2.offset, l1.offset);
  Ratio divided = ratio_divide(right_side, left_side);
  return divided;
}

int li_cost(int ax, int ay, int bx, int by, int px, int py) {
  Line b_line;
  b_line.slope.num = by;
  b_line.slope.denom = bx;
  b_line.offset.num = 0;
  b_line.offset.denom = 1;

  Line a_line;
  a_line.slope.num = ay;
  a_line.slope.denom = ax;
  a_line.offset.num = -1 * ((px * ay) - (py * ax));
  a_line.offset.denom = ax;
  
  Ratio r = intersect_x(b_line, a_line);

  if (!proper(r)) {
    printf("bzzt\n");
    return 0;
  }

  long b_x_movement = (r.num / r.denom);
  long b_cost = b_x_movement / bx;
  long a_x_movement = px - b_x_movement;
  long a_cost = a_x_movement / ax;
  printf("%d\n", b_cost + a_cost);
  return b_cost + a_cost;
}

int best_cost(int ax, int ay, int bx, int by, int px, int py) {
  int best_cost_so_far = 0;
  
  for (int i = 0; i <= 100; i++) {
    px -= ax;
    py -= ay;
    if (px % bx != 0 || py % by != 0) continue;
    if (px / bx != py / by) continue;

    int cost = (i + 1) * 3 + px / bx;
    if (best_cost_so_far == 0 || best_cost_so_far > cost) best_cost_so_far = cost;
  }

  return best_cost_so_far;
}

int main() {
  int ax, ay, bx, by, px, py;
  char *line;

  int cost = 0;
  int cost_2 = 0;
  while((line = aoc_read_line()) != NULL) {
    sscanf(line, "Button A: X+%d, Y+%d", &ax, &ay);
    sscanf(aoc_read_line(), "Button B: X+%d, Y+%d", &bx, &by);
    sscanf(aoc_read_line(), "Prize: X=%d, Y=%d", &px, &py);
    aoc_read_line();

    cost += li_cost(ax, ay, bx, by, px, py);
    cost_2 += li_cost(ax, ay, bx, by, px + 10000000000000, py + 10000000000000);
  }

  printf("Part 1: %d\n", cost);
  printf("Part 2: %lld\n", cost_2);
  
  aoc_free();
  return 0;
}