diff options
| author | Marvin Borner | 2021-12-01 06:21:23 +0100 |
|---|---|---|
| committer | Marvin Borner | 2021-12-01 06:25:13 +0100 |
| commit | 057b901937b84e3b702215eb01b0b68f3dfb8274 (patch) | |
| tree | 87eb814d2070e7f2f1f77e51457003a94f1d583c /2021/01/solve.c | |
| parent | 3aa641542918765f6ceb039cfa64ff6f58597eb2 (diff) | |
tired
Diffstat (limited to '2021/01/solve.c')
| -rw-r--r-- | 2021/01/solve.c | 86 |
1 files changed, 86 insertions, 0 deletions
diff --git a/2021/01/solve.c b/2021/01/solve.c new file mode 100644 index 0000000..404ba2c --- /dev/null +++ b/2021/01/solve.c @@ -0,0 +1,86 @@ +#include <stdio.h> +#include <stdlib.h> +#include <time.h> + +#define FORLINE \ + char *line = NULL; \ + size_t len = 0; \ + while (getline(&line, &len, fp) != EOF) +#define FREELINE \ + if (line) \ + free(line) + +#define FORCH \ + char ch = 0; \ + while ((ch = fgetc(fp)) != EOF) + +#define WHOLE \ + fseek(fp, 0, SEEK_END); \ + long fsize = ftell(fp); \ + fseek(fp, 0, SEEK_SET); \ + char *data = malloc(fsize + 1); \ + fread(data, 1, fsize, fp); \ + data[fsize] = 0; \ + data[fsize--] = 0 + +static int part_one(FILE *fp) +{ + int res = 0xffffffff; + + int prev = 0; + FORLINE + { + int strength = atoi(line); + if (strength > prev) + res++; + prev = strength; + } + FREELINE; + + return res; +} + +static int part_two(FILE *fp) +{ + int res = 0; + + int prevstrength = -1; + + int prevprev = -1; + int prev = -1; + FORLINE + { + int orig = atoi(line); + int strength = 0; + if (prevprev > 0 && prev > 0) + strength = orig + prev + prevprev; + if (prevstrength > 0 && strength > prevstrength) + res++; + prevstrength = strength; + prevprev = prev; + prev = orig; + } + FREELINE; + + return res; +} + +int main(int argc, char *argv[]) +{ + (void)argc; + (void)argv; + + FILE *fp = fopen("input", "r"); + if (!fp) + exit(EXIT_FAILURE); + + clock_t tic = clock(); + printf("%d\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; +} |