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day 7 part 2 (C), day 8 init

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Bruno Raoult
2021-12-10 12:06:23 +01:00
parent 6f6a6b286a
commit e871ccf091
8 changed files with 385 additions and 13 deletions
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33
2021/day07/aoc-c.c
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@@ -28,7 +28,7 @@ typedef struct crab {
crab_t *crabs = NULL;
//#ifdef DEBUG
#ifdef DEBUG
static void print_crab()
{
int i = 0;
@@ -38,7 +38,7 @@ static void print_crab()
printf("%s%d/%d", i? ", ": "", crabs[i].pos, crabs[i].ncrabs);
printf("\n");
}
//#endif
#endif
static crab_t *grow_crabs()
{
@@ -93,19 +93,30 @@ static u64 read_crab()
return ncrabs;
}
static int doit(int part)
static u64 doit(int part)
{
int try, best_dist = 0, best_fuel = crab_max * crab_max;
int try;
u64 best_fuel = (u64) -1;
if (part == 1) {
for (try = 0; try < crab_max; ++try) {
int fuel = 0;
for (int crab = 0; crab < ncrabs; ++crab)
u64 fuel = 0;
for (int crab = 0; crab < ncrabs; ++crab) {
fuel += abs(crabs[crab].pos - try) * crabs[crab].ncrabs;
if (fuel < best_fuel) {
best_dist = try;
best_fuel = fuel;
}
if (fuel < best_fuel)
best_fuel = fuel;
}
} else {
for (try = 0; try < crab_max; ++try) {
u64 fuel = 0;
for (int crab = 0; crab < ncrabs; ++crab) {
/* n * (n + 1) / 2 */
fuel += abs(crabs[crab].pos - try) *
(abs(crabs[crab].pos - try) + 1) * crabs[crab].ncrabs / 2;
}
if (fuel < best_fuel)
best_fuel = fuel;
}
}
return best_fuel;
@@ -121,7 +132,7 @@ int main(int ac, char **av)
{
int opt;
u32 exercise = 1;
int res;
u64 res;
while ((opt = getopt(ac, av, "d:p:")) != -1) {
switch (opt) {
@@ -142,6 +153,6 @@ int main(int ac, char **av)
read_crab();
res = doit(exercise);
printf ("%s : res=%d\n", *av, res);
printf ("%s : res=%lu\n", *av, res);
exit (0);
}