I will improve this soon ARGH

1 files changed, 47 insertions, 8 deletions

diff --git a/2020/14/solve.c b/2020/14/solve.c
index 4ca91fd..e2233dc 100644
--- a/2020/14/solve.c
+++ b/2020/14/solve.c
@@ -3,7 +3,7 @@
 #include <time.h>
 
 struct mem_entry {
-	int address;
+	long address;
 	long value;
 	struct mem_entry *next;
 };
@@ -27,8 +27,12 @@ struct mem_entry *get_entry(struct mem_map *mem_map, int address)
 	return NULL;
 }
 
-void new_entry(struct mem_map *mem_map, int address, long value)
+void new_entry(struct mem_map *mem_map, long address, long value)
 {
+	/* printf("%lu: %lu\n", address, value); */
+	if (!mem_map)
+		return;
+
 	struct mem_entry *override = NULL;
 	if ((override = get_entry(mem_map, address))) {
 		override->value = value;
@@ -68,7 +72,7 @@ long part_one(FILE *fp)
 	char *line = NULL;
 	size_t len = 0;
 	char mask[36] = { 0 };
-	struct mem_map mem_map[256] = { 0 };
+	struct mem_map mem_map = { 0 };
 	while (getline(&line, &len, fp) != -1) {
 		if (line[0] == 'm' && line[1] == 'a') {
 			sscanf(line, "mask = %s\n", &mask[0]);
@@ -83,16 +87,51 @@ long part_one(FILE *fp)
 				else if (*p == '1')
 					value |= shift;
 			}
-			new_entry(mem_map, address, value);
+			new_entry(&mem_map, address, value);
 		}
 	}
 
-	return count_doku(mem_map);
+	return count_doku(&mem_map);
 }
 
-int part_two(FILE *fp)
+long part_two(FILE *fp)
 {
-	return 0;
+	char *line = NULL;
+	size_t len = 0;
+	char mask[36] = { 0 };
+	int floating_bits[64];
+	struct mem_map mem_map = { 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') {
+			long address = 0, value = 0;
+			sscanf(line, "mem[%lu] = %lu\n", &address, &value);
+
+			int floating = 0;
+			for (int i = 0; i < 36; i++) {
+				if (mask[i] == '1') {
+					address |= 1L << (36 - i - 1);
+				} else if (mask[i] == 'X') {
+					floating_bits[floating] = i;
+					floating++;
+				}
+			}
+
+			long masked_addr = address;
+			for (long perm = 0; perm < (1 << floating); ++perm) {
+				long address = masked_addr;
+				for (int j = 0; j < floating; ++j) {
+					if (perm & (1L << j)) {
+						address ^= (1L << (36 - floating_bits[j] - 1));
+					}
+				}
+				new_entry(&mem_map, address, value);
+			}
+		}
+	}
+
+	return count_doku(&mem_map);
 }
 
 int main(int argc, char *argv[])
@@ -104,7 +143,7 @@ int main(int argc, char *argv[])
 	clock_t tic = clock();
 	printf("%lu\n", part_one(fp));
 	rewind(fp);
-	printf("%d\n", part_two(fp));
+	printf("%lu\n", part_two(fp));
 	clock_t toc = clock();
 	printf("TIME: %f seconds\n", (double)(toc - tic) / CLOCKS_PER_SEC);