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#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <time.h>
int part_one(char *data)
{
// Strange parsing
int note_earliest = 0, note_line = 0, note_service_index = 0;
int note_in_service[128] = { 0 };
for (char *p = data; *p; p++) {
if (*p == '\n') {
note_line++;
continue;
} else if (*p == 'x') {
p++;
continue;
}
if (!note_earliest && note_line == 0) {
sscanf(p, "%d\n", ¬e_earliest);
} else if (note_earliest && note_line == 1) {
sscanf(p, "%d,", ¬e_in_service[note_service_index]);
p += (int)(floor(log10(note_in_service[note_service_index])) + 1); // idk
note_service_index++;
}
}
// Strange loops
for (int time = note_earliest;; time++) {
for (int *bus = note_in_service; *bus != 0; bus++) {
if (time % *bus == 0)
return (time - note_earliest) * *bus;
}
}
}
long part_two(char *data)
{
int note_line = 0, note_service_index = 0;
int note_in_service[128] = { 0 };
for (char *p = data; *p; p++) {
if (*p == '\n') {
note_line++;
continue;
}
if (note_line == 1) {
if (*p == 'x') {
note_in_service[note_service_index] = 0;
p += 1;
} else {
sscanf(p, "%d,", ¬e_in_service[note_service_index]);
p += (int)(floor(log10(note_in_service[note_service_index])) + 1);
}
note_service_index++;
}
}
long pos = 0, offset = 1;
for (int *bus = note_in_service; bus - note_in_service < note_service_index; bus++) {
if (!*bus)
continue;
while ((pos + (bus - note_in_service)) % *bus)
pos += offset;
offset *= *bus;
}
return pos;
}
#define SIZE 20000
int main(int argc, char *argv[])
{
FILE *fp = fopen("input", "r");
if (!fp)
exit(EXIT_FAILURE);
char buf[SIZE] = { 0 };
fread(buf, SIZE, 1, fp);
clock_t tic = clock();
printf("%d\n", part_one(buf));
printf("%lu\n", part_two(buf));
clock_t toc = clock();
printf("TIME: %f seconds\n", (double)(toc - tic) / CLOCKS_PER_SEC);
fclose(fp);
return 0;
}
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