Overcomplicated but fun solution for 14a

1 files changed, 113 insertions, 0 deletions

diff --git a/2020/14/solve.c b/2020/14/solve.c
new file mode 100644
index 0000000..4ca91fd
--- /dev/null
+++ b/2020/14/solve.c
@@ -0,0 +1,113 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+struct mem_entry {
+	int address;
+	long value;
+	struct mem_entry *next;
+};
+
+struct mem_map {
+	struct mem_entry *head;
+	struct mem_entry *tail;
+};
+
+struct mem_entry *get_entry(struct mem_map *mem_map, int address)
+{
+	if (!mem_map || !mem_map->head || !mem_map->tail)
+		return NULL;
+
+	struct mem_entry *iterator = mem_map->head;
+	while (iterator) {
+		if (iterator->address == address)
+			return iterator;
+		iterator = iterator->next;
+	}
+	return NULL;
+}
+
+void new_entry(struct mem_map *mem_map, int address, long value)
+{
+	struct mem_entry *override = NULL;
+	if ((override = get_entry(mem_map, address))) {
+		override->value = value;
+		return;
+	}
+
+	struct mem_entry *new = malloc(sizeof(*new));
+	new->address = address;
+	new->value = value;
+	new->next = NULL;
+
+	if (mem_map->head && mem_map->tail) {
+		mem_map->tail->next = new;
+		mem_map->tail = new;
+	} else {
+		mem_map->head = new;
+		mem_map->tail = mem_map->head;
+	}
+}
+
+long count_doku(struct mem_map *mem_map)
+{
+	if (!mem_map || !mem_map->head || !mem_map->tail)
+		return 0;
+
+	long cnt = 0;
+	struct mem_entry *iterator = mem_map->head;
+	while (iterator) {
+		cnt += iterator->value;
+		iterator = iterator->next;
+	}
+	return cnt;
+}
+
+long part_one(FILE *fp)
+{
+	char *line = NULL;
+	size_t len = 0;
+	char mask[36] = { 0 };
+	struct mem_map mem_map[256] = { 0 };
+	while (getline(&line, &len, fp) != -1) {
+		if (line[0] == 'm' && line[1] == 'a') {
+			sscanf(line, "mask = %s\n", &mask[0]);
+		} else if (line[0] == 'm' && line[1] == 'e') {
+			int address;
+			long value;
+			sscanf(line, "mem[%d] = %lu\n", &address, &value);
+			for (char *p = mask; *p; p++) {
+				long shift = 1ul << (35 - (p - mask));
+				if (*p == '0')
+					value &= ~shift;
+				else if (*p == '1')
+					value |= shift;
+			}
+			new_entry(mem_map, address, value);
+		}
+	}
+
+	return count_doku(mem_map);
+}
+
+int part_two(FILE *fp)
+{
+	return 0;
+}
+
+int main(int argc, char *argv[])
+{
+	FILE *fp = fopen("input", "r");
+	if (!fp)
+		exit(EXIT_FAILURE);
+
+	clock_t tic = clock();
+	printf("%lu\n", part_one(fp));
+	rewind(fp);
+	printf("%d\n", part_two(fp));
+	clock_t toc = clock();
+	printf("TIME: %f seconds\n", (double)(toc - tic) / CLOCKS_PER_SEC);
+
+	fclose(fp);
+	return 0;
+}