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2022 day 15 part 2 (C). First version: 18s, ~30,000,000 func calls

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Bruno Raoult
2023-04-02 19:45:55 +02:00
parent 5ad5c87fd8
commit 34b6cd7b57
1 changed files with 166 additions and 83 deletions
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249
2022/day15/aoc-c.c
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@@ -27,6 +27,7 @@
#include "aoc.h"
static pool_t *pool_segment, *pool_row, *pool_pair;
static int inner_count;
#define HBITS 20 /* 20 bits: 1,048,576 buckets */
static DEFINE_HASHTABLE(hasht_rows, HBITS);
@@ -35,35 +36,36 @@ struct coord {
int x, y;
};
#define TOP 0
#define RIGHT 1
#define BOTTOM 2
#define LEFT 3
/**
* struct pair - input file pair list
* @sensor, @beacon: struct coord sensor and beacon coordinates.
* @manhattan: manhattan distance between sensor and beacon.
* @parity: beacon coordinates parity (as bishop color in chess).
* @top, @right, @bottom, @left: coordinates of rhombus immediately out
* range of sensor.
* @corners: coordinates of rhombus immediately out of sensor range (clockwise).
* @list: list of pairs.
*/
struct pair {
struct coord sensor, beacon;
int manhattan;
int parity;
struct coord top, bottom, left, right;
struct coord corners[4];
struct list_head list;
};
LIST_HEAD(pairs_head);
/**
* struct map - full map
* @xmin, @xmax: most left/right x-coordinates.
* @ymin, @ymax: most top/bottom y-coordinates.
* @min, @max: map's min and max coordinates.
* @hash: rows hash table
*/
struct map {
struct coord min, max; //int xmin, xmax, ymin, ymax;
struct coord min, max;
struct hlist_head *hash;
} map = {
//INT_MAX, INT_MIN, INT_MAX, INT_MIN, hasht_rows
.min = { INT_MIN, INT_MIN }, .max = {INT_MAX, INT_MAX }, hasht_rows
};
@@ -231,6 +233,7 @@ static struct row *add_segment(int row, int center, int half)
int x1, x2;
uint hash = row, bucket = hash_32(hash, HBITS);
struct row *prow = find_row(&map.hash[bucket], hash);
inner_count++;
x1 = max(center - half, map.min.x);
x2 = min(center + half, map.max.x);
@@ -254,14 +257,22 @@ static struct row *add_segment(int row, int center, int half)
}
/**
* is_off_range() - test if a point is off range from a sensor
* is_off_range() - test if a point is off range from all sensors.
*/
static int is_off_range(struct pair *pair, struct coord *point)
static int is_off_range(struct coord *point)
{
return (abs(point->x - pair->sensor.x)
+ abs(point->y - pair->sensor.y)) > pair->manhattan;
struct pair *pair;
/* reverse loop, because higher manhattan means higher chances to fail */
list_for_each_entry_reverse(pair, &pairs_head, list) {
if ((abs(point->x - pair->sensor.x) +
abs(point->y - pair->sensor.y)) <= pair->manhattan)
return 0;
}
return 1;
}
static int add_segments(struct pair *pair)
{
int manhattan = pair->manhattan,
@@ -293,8 +304,10 @@ static void print_pairs()
pair->sensor.x, pair->sensor.y,
pair->beacon.x, pair->beacon.y);
printf(" top=(%d,%d) bottom=(%d,%d) left=(%d,%d) right=(%d,%d)\n",
pair->top.x, pair->top.y, pair->bottom.x, pair->bottom.y,
pair->left.x, pair->left.y, pair->right.x, pair->right.y);
pair->corners[TOP].x, pair->corners[TOP].y,
pair->corners[BOTTOM].x, pair->corners[BOTTOM].y,
pair->corners[LEFT].x, pair->corners[LEFT].y,
pair->corners[RIGHT].x, pair->corners[RIGHT].y);
}
}
@@ -312,19 +325,18 @@ static struct pair *parse()
pair->beacon = beacon;
pair->manhattan = abs(beacon.x - sensor.x) + abs(beacon.y - sensor.y);
pair->parity = (pair->beacon.x + pair->beacon.y) % 2;
pair->top = (struct coord) { sensor.x, sensor.y - pair->manhattan - 1 };
pair->bottom = (struct coord) { sensor.x, sensor.y + pair->manhattan + 1 };
pair->right = (struct coord) { sensor.x + pair->manhattan + 1, sensor.y };
pair->left = (struct coord) { sensor.x - pair->manhattan - 1, sensor.y };
pair->corners[TOP] = (struct coord) { sensor.x, sensor.y - pair->manhattan - 1 };
pair->corners[BOTTOM] = (struct coord) { sensor.x, sensor.y + pair->manhattan + 1 };
pair->corners[RIGHT] = (struct coord) { sensor.x + pair->manhattan + 1, sensor.y };
pair->corners[LEFT] = (struct coord) { sensor.x - pair->manhattan - 1, sensor.y };
if (list_empty(&pairs_head)) {
list_add(&pair->list, &pairs_head);
goto end;
}
list_for_each_entry(cur, &pairs_head, list) {
if (cur->manhattan > pair->manhattan) {
list_add_tail(&pair->list, &cur->list);
goto end;
/* keep list ordered by manhattan */
if (!list_empty(&pairs_head)) {
list_for_each_entry(cur, &pairs_head, list) {
if (cur->manhattan > pair->manhattan) {
list_add_tail(&pair->list, &cur->list);
goto end;
}
}
}
list_add_tail(&pair->list, &pairs_head);
@@ -382,75 +394,144 @@ static ulong part2()
}
/**
* intersect() - return two segments intersection.
* /#\
* /#\ /# #\
* /# #\ /# #\
* /# #\O/# <--- O is a possible point
* #X#
* rhomb A /#\ rhom B
* /# #\
* /# #\
* /# #\
* /# #\
* /# rhombs #\
* A & B
* (intersection)
*/
static int intersect(float p0_x, float p0_y, float p1_x, float p1_y,
float p2_x, float p2_y, float p3_x, float p3_y, float *i_x, float *i_y)
/**
* intersect() - find intersection of two segments
*
*/
static struct coord *intersect(struct coord *p1, struct coord *p2,
struct coord *q1, struct coord *q2,
struct coord *ret)
{
float s02_x, s02_y, s10_x, s10_y, s32_x, s32_y, s_numer, t_numer, denom, t;
s10_x = p1_x - p0_x;
s10_y = p1_y - p0_y;
s32_x = p3_x - p2_x;
s32_y = p3_y - p2_y;
int a1, a2, b1, b2, x, y;
a1 = (p2->y - p1->y) / (p2->x - p1->x);
a2 = (q2->y - q1->y) / (q2->x - q1->x);
b1 = p1->y - p1->x * a1;
b2 = q1->y - q1->x * a2;
x = (b2 - b1) / (a1 - a2);
y = a1 * x + b1;
inner_count++;
denom = s10_x * s32_y - s32_x * s10_y;
if (denom == 0)
return 0; // Collinear
bool denomPositive = denom > 0;
s02_x = p0_x - p2_x;
s02_y = p0_y - p2_y;
s_numer = s10_x * s02_y - s10_y * s02_x;
if ((s_numer < 0) == denomPositive)
return 0; // No collision
t_numer = s32_x * s02_y - s32_y * s02_x;
if ((t_numer < 0) == denomPositive)
return 0; // No collision
if (((s_numer > denom) == denomPositive) || ((t_numer > denom) == denomPositive))
return 0; // No collision
// Collision detected
t = t_numer / denom;
if (i_x != NULL)
*i_x = p0_x + (t * s10_x);
if (i_y != NULL)
*i_y = p0_y + (t * s10_y);
return 1;
log_f(3, "p1=(%d,%d) p2=(%d,%d) q1=(%d,%d) q2=(%d,%d)\n",
p1->x, p1->y, p2->x, p2->y,
q1->x, q1->y, q2->x, q2->y);
log(3, "\ta1=%d b1=%d a2=%d b2=%d\n", a1, b1, a2, b2);
/* Intersection is at:
* (x * a1) + b1 = (x * a2) + b2
* x * (a1 - a2) = b2 - b1
* x = (b2 - b1) / (a1 - a2)
*/
if (x >= min(p1->x, p2->x) && x >= min(q1->x, q2->x) &&
x <= max(p1->x, p2->x) && x <= max(q1->x, q2->x) &&
y >= min(p1->y, p2->y) && y >= min(q1->y, q2->y) &&
y <= max(p1->y, p2->y) && y <= max(q1->y, q2->y) &&
x >= map.min.x && x <= map.max.x &&
y >= map.min.y && y <= map.max.y) {
log(3, "\tintersection=(%d,%d)\n", ret->x, ret->y);
*ret = (struct coord) {x, y};
} else {
log(3, "\tOUT=(%d,%d)\n", x, y);
log(3, "xmin(p)=%d xmax(p)=%d xmin(q)=%d, xmax(q)=%d\n",
min(p1->x, p2->x), max(p1->x, p2->x),
min(q1->x, q2->x), max(q1->x, q2->x));
log(3, "ymin(p)=%d ymax(p)=%d ymin(q)=%d, ymax(q)=%d\n",
min(p1->y, p2->y), max(p1->y, p2->y),
min(q1->y, q2->y), max(q1->y, q2->y));
log(3, "xmin=%d xmax=%d ymin=%d, ymax=%d\n",
map.min.x, map.max.x, map.min.y, map.max.y);
ret = NULL;
}
return ret;
}
#define T_R(p) &p->corners[TOP], &p->corners[RIGHT]
#define R_B(p) &p->corners[RIGHT], &p->corners[BOTTOM]
#define B_L(p) &p->corners[BOTTOM], &p->corners[LEFT]
#define L_T(p) &p->corners[LEFT], &p->corners[TOP]
struct coord *check_intersect(struct coord *ret)
{
struct pair *pair, *second;
log_f(1, "****************\n");
list_for_each_entry(pair, &pairs_head, list) {
int i = 0;
if (pair->corners[TOP].x == 3036853 ||
pair->corners[RIGHT].x == 3036853 ||
pair->corners[BOTTOM].x == 3036853 ||
pair->corners[LEFT].x == 3036853) {
printf("m=%d p=%s s=(%d,%d) b=(%d,%d)\n",
pair->manhattan,
pair->parity? "WHITE": "BLACK",
pair->sensor.x, pair->sensor.y,
pair->beacon.x, pair->beacon.y);
printf(" top=(%d,%d) bottom=(%d,%d) left=(%d,%d) right=(%d,%d)\n",
pair->corners[TOP].x, pair->corners[TOP].y,
pair->corners[BOTTOM].x, pair->corners[BOTTOM].y,
pair->corners[LEFT].x, pair->corners[LEFT].y,
pair->corners[RIGHT].x, pair->corners[RIGHT].y);
}
second = list_prepare_entry(pair, &pairs_head, list);
list_for_each_entry_continue(second, &pairs_head, list) {
printf("\t\t%d -> m=%d p=%s s=(%d,%d) b=(%d,%d)\n",
++i,
second->manhattan,
second->parity? "WHITE": "BLACK",
second->sensor.x, second->sensor.y,
second->beacon.x, second->beacon.y);
if (second->parity == pair->parity) {
/* top right segment */
if ((intersect(T_R(pair), R_B(second), ret) && is_off_range(ret)) ||
(intersect(T_R(pair), L_T(second), ret) && is_off_range(ret)))
return ret;
/* bottom left segment */
if ((intersect(B_L(pair), R_B(second), ret) && is_off_range(ret)) ||
(intersect(B_L(pair), L_T(second), ret) && is_off_range(ret)))
return ret;
/* right bottom segment */
if ((intersect(R_B(pair), T_R(second), ret) && is_off_range(ret)) ||
(intersect(R_B(pair), B_L(second), ret) && is_off_range(ret)))
return ret;
/* left top segment */
if ((intersect(L_T(pair), T_R(second), ret) && is_off_range(ret)) ||
(intersect(L_T(pair), B_L(second), ret) && is_off_range(ret)))
return ret;
} else {
printf("parity skip\n");
}
}
}
return NULL;
}
//static int is_inside(int x, int y, )
static ulong part2_new()
{
ulong res = 0;
struct pair *pair;
struct coord result;
map.min.x = map.min.y = 0;
map.max.x = map.max.y = testmode()? 20: 4000000;
while ((pair = parse())) {
//int outside = pair->manhattan + 1;
//add_segments(pair);
//log(3, "m=%d : ", manhattan);
}
while (parse())
;
print_pairs();
return res;
for (int row = map.min.y; row <= map.max.y; ++row) {
uint bucket = hash_32(row, HBITS);
struct row *prow = find_row(&map.hash[bucket], row);
if (!prow) {
printf("fuck 1: prow(%d)=NULL\n", row);
exit(1);
}
struct segment *cur;
cur = list_first_entry(&prow->segments, struct segment, list);
if (cur->end != map.max.x) {
res = ((u64)cur->end + 1UL) * 4000000UL + (u64)row;
break;
}
}
check_intersect(&result);
printf("result=(%d,%d)\n", result.x, result.y);
res = ((u64)result.x) * 4000000UL + (u64)result.x;
return res;
}
@@ -463,9 +544,11 @@ int main(int ac, char **av)
pool_segment = pool_create("segments", 8192, sizeof(struct segment));
pool_pair = pool_create("pair", 32, sizeof(struct pair));
part2_new();
exit(1);
//part2_new();
//printf("loops=%d\n", inner_count);
//exit(1);
printf("%s: res=%lu\n", *av, part == 1? part1(): part2());
printf("loops=%d\n", inner_count);
pool_destroy(pool_row);
pool_destroy(pool_segment);
pool_destroy(pool_pair);