diff options
| -rw-r--r-- | 04.c | 152 | ||||
| -rw-r--r-- | Makefile | 5 |
2 files changed, 156 insertions, 1 deletions
@@ -0,0 +1,152 @@ +#include <stdlib.h> +#include <stdio.h> +#include <err.h> +#include <stdbool.h> +#include "input.h" + +#define INPUT "input/04.txt" +#define BOARD_COUNT 100 +#define BOARD_SIZE 5 +#define MAX_DRAW 500 + +typedef struct { + long board[BOARD_SIZE][BOARD_SIZE]; + bool board_marks[BOARD_SIZE][BOARD_SIZE]; +} t_board; + +bool board_is_winning(t_board* board) { + for(int i = 0; i < BOARD_SIZE; i++) { + bool winning_i = true; + bool winning_j = true; + for(int j = 0; j < BOARD_SIZE; j++) { + winning_i &= board->board_marks[i][j]; + winning_j &= board->board_marks[j][i]; + } + if(winning_i || winning_j) + return true; + } + return false; +} + +bool board_mark(t_board* board, long draw) { + for(int i = 0; i < BOARD_SIZE; i++) { + for(int j = 0; j < BOARD_SIZE; j++) { + if(board->board[i][j] == draw) + board->board_marks[i][j] = true; + } + } + return board_is_winning(board); +} + +void board_init(t_board* board) { + for(int i = 0; i < BOARD_SIZE; i++) { + for(int j = 0; j < BOARD_SIZE; j++) { + board->board[i][j] = 0; + board->board_marks[i][j] = false; + } + } +} + +void board_read(t_board* board_list, struct input_str* input) { + for(int i = 0; i < BOARD_COUNT; i++) { + board_init(&(board_list[i])); + // read each line of the board + for(int j = 0; j < BOARD_SIZE; j++) { + // + 2 is for first line and empty line at start of board + int line_index = i * (BOARD_SIZE + 1) + j + 2; + char* line = input->lines[line_index]; + char* start = line; + char* end = NULL; + // read each int + for(int k = 0; k < BOARD_SIZE; k++) { + board_list[i].board[j][k] = strtol(start, &end, 0); + start = end; + } + } + } +} + +size_t draw_read(long* draw_list, struct input_str* input) { + size_t i = 0; + char *start = input->lines[0]; + char *end = start; + while(i < MAX_DRAW && *end != '\n') { + draw_list[i] = strtol(start, &end, 0); + start = end + 1; + i++; + } + if(i == MAX_DRAW && *end != '\n') + err(1, "draw list was truncated"); + + return i; +} + +long board_unmarked_sum(t_board* board) { + long sum = 0; + for(int i = 0; i < BOARD_SIZE; i++) { + for(int j = 0; j < BOARD_SIZE; j++) { + if(!(board->board_marks)[i][j]) + sum += (board->board)[i][j]; + } + } + return sum; +} + +void part1(struct input_str* input) { + t_board board_list[BOARD_COUNT]; + long draw_list[MAX_DRAW]; + board_read(board_list, input); + size_t draw_count = draw_read(draw_list, input); + + // apply draw to each board until one is winning + for(size_t i = 0; i < draw_count; i++) { + for(size_t j = 0; j < BOARD_COUNT; j++) { + if(board_mark(&(board_list[j]), draw_list[i])) { + // winning board found, print score + long score = board_unmarked_sum(&(board_list[j])); + printf("%ld\n", draw_list[i] * score); + return; + } + } + } + + err(1, "no winning board"); +} + +void part2(struct input_str* input) { + t_board board_list[BOARD_COUNT]; + long draw_list[MAX_DRAW]; + board_read(board_list, input); + size_t draw_count = draw_read(draw_list, input); + + // apply draw to each board until one is winning + long last_score; + for(size_t i = 0; i < draw_count; i++) { + for(size_t j = 0; j < BOARD_COUNT; j++) { + // skip already winning boards + if(board_is_winning(&(board_list[j]))) + continue; + + if(board_mark(&(board_list[j]), draw_list[i])) { + // winning board found + last_score = draw_list[i] * board_unmarked_sum(&(board_list[j])); + } + } + } + // print last winning + printf("%ld\n", last_score); +} + +int main() { + // read input + struct input_str input; + input_str_read(&input, INPUT); + + // do stuff + part1(&input); + part2(&input); + + // cleanup & exit + input_str_free(&input); + return 0; +} @@ -1,7 +1,7 @@ CC=cc CFLAGS=-std=c1x -W -Wall -g LDFLAGS= -EXEC=01 02 03 +EXEC=01 02 03 04 all: $(EXEC) @@ -14,6 +14,9 @@ all: $(EXEC) 03: input.o 03.o $(CC) -o $@ $> $(LDFLAGS) +04: input.o 04.o + $(CC) -o $@ $> $(LDFLAGS) + .c.o: $(CC) -o $@ -c $< $(CFLAGS) |