+void* xmalloc(size_t size)
+{
+ void* ptr = malloc(size);
+ if (ptr == NULL) {
+ // LCOV_EXCL_START
+ // exclude from coverage analysis because we can't simulate an out of memory error in testing
+ fprintf(stderr, "Out of memory!\n");
+ exit(EXIT_FAILURE);
+ // LCOV_EXCL_STOP
+ }
+ return (ptr);
+}
+
+void packed_to_token(long packed, char token[6])
+{
+ // The advent->ascii mapping.
+ const char advent_to_ascii[] = {
+ ' ', '!', '"', '#', '$', '%', '&', '\'',
+ '(', ')', '*', '+', ',', '-', '.', '/',
+ '0', '1', '2', '3', '4', '5', '6', '7',
+ '8', '9', ':', ';', '<', '=', '>', '?',
+ '@', 'A', 'B', 'C', 'D', 'E', 'F', 'G',
+ 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O',
+ 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W',
+ 'X', 'Y', 'Z', '\0', '\0', '\0', '\0', '\0',
+ };
+
+ // Unpack and map back to ASCII.
+ for (int i = 0; i < 5; ++i) {
+ char advent = (packed >> i * 6) & 63;
+ token[i] = advent_to_ascii[(int) advent];
+ }
+
+ // Ensure the last character is \0.
+ token[5] = '\0';
+
+ // Replace trailing whitespace with \0.
+ for (int i = 4; i >= 0; --i) {
+ if (token[i] == ' ' || token[i] == '\t')
+ token[i] = '\0';
+ else
+ break;
+ }
+}
+
+long token_to_packed(const char token[6])
+{
+ const char ascii_to_advent[] = {
+ 63, 63, 63, 63, 63, 63, 63, 63,
+ 63, 63, 63, 63, 63, 63, 63, 63,
+ 63, 63, 63, 63, 63, 63, 63, 63,
+ 63, 63, 63, 63, 63, 63, 63, 63,
+
+ 0, 1, 2, 3, 4, 5, 6, 7,
+ 8, 9, 10, 11, 12, 13, 14, 15,
+ 16, 17, 18, 19, 20, 21, 22, 23,
+ 24, 25, 26, 27, 28, 29, 30, 31,
+ 32, 33, 34, 35, 36, 37, 38, 39,
+ 40, 41, 42, 43, 44, 45, 46, 47,
+ 48, 49, 50, 51, 52, 53, 54, 55,
+ 56, 57, 58, 59, 60, 61, 62, 63,
+
+ 63, 63, 63, 63, 63, 63, 63, 63,
+ 63, 63, 63, 63, 63, 63, 63, 63,
+ 63, 63, 63, 63, 63, 63, 63, 63,
+ 63, 63, 63, 63, 63, 63, 63, 63,
+ };
+
+ size_t t_len = strlen(token);
+ long packed = 0;
+ for (size_t i = 0; i < t_len; ++i) {
+ char mapped = ascii_to_advent[(int) token[i]];
+ packed |= (mapped << (6 * i));
+ }
+ return (packed);
+}
+
+void tokenize(char* raw, long tokens[4])
+{
+ // set each token to 0
+ for (int i = 0; i < 4; ++i)
+ tokens[i] = 0;
+
+ // grab the first two words
+ char* words[2];
+ words[0] = (char*) xmalloc(strlen(raw) + 1);
+ words[1] = (char*) xmalloc(strlen(raw) + 1);
+ int word_count = sscanf(raw, "%s%s", words[0], words[1]);
+
+ // make space for substrings and zero it out
+ char chunk_data[][6] = {
+ {"\0\0\0\0\0"},
+ {"\0\0\0\0\0"},
+ {"\0\0\0\0\0"},
+ {"\0\0\0\0\0"},
+ };
+
+ // break the words into up to 4 5-char substrings
+ sscanf(words[0], "%5s%5s", chunk_data[0], chunk_data[1]);
+ if (word_count == 2)
+ sscanf(words[1], "%5s%5s", chunk_data[2], chunk_data[3]);
+ free(words[0]);
+ free(words[1]);
+
+ // uppercase all the substrings
+ for (int i = 0; i < 4; ++i)
+ for (unsigned int j = 0; j < strlen(chunk_data[i]); ++j)
+ chunk_data[i][j] = (char) toupper(chunk_data[i][j]);
+
+ // pack the substrings
+ for (int i = 0; i < 4; ++i)
+ tokens[i] = token_to_packed(chunk_data[i]);
+}
+
+/* Hide the fact that wods are corrently packed longs */
+
+bool wordeq(token_t a, token_t b)
+{
+ return a == b;
+}