2020 day 8 (C, both parts. No inspiration here)

This commit is contained in:
2022-12-12 20:46:09 +01:00
parent 25d25b399e
commit 31a255a9ac
3 changed files with 173 additions and 6 deletions

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@@ -153,7 +153,7 @@ aoc-c: res=7490863
context-switch: 0+1, page-faults: 0+98
=========================================
================= day07 =================
================= day08 =================
=========================================
+++++++++++++++++ part 1
@@ -161,7 +161,15 @@ aoc.bash: res=1698
time: 0:01.10 real, 1.10 user, 0.00 sys
context-switch: 5+1, page-faults: 0+319
aoc-c: res=1698
time: 0:00.00 real, 0.00 user, 0.00 sys
context-switch: 0+1, page-faults: 0+92
+++++++++++++++++ part 2
aoc.bash: res=672280
time: 0:03.54 real, 3.53 user, 0.00 sys
context-switch: 48+1, page-faults: 0+284
aoc-c: res=672280
time: 0:00.00 real, 0.00 user, 0.00 sys
context-switch: 0+1, page-faults: 0+91

159
2022/day08/aoc-c.c Normal file
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@@ -0,0 +1,159 @@
/* aoc-c.c: Advent of Code 2022, day 8
*
* Copyright (C) 2022 Bruno Raoult ("br")
* Licensed under the GNU General Public License v3.0 or later.
* Some rights reserved. See COPYING.
*
* You should have received a copy of the GNU General Public License along with this
* program. If not, see <https://www.gnu.org/licenses/gpl-3.0-standalone.html>.
*
* SPDX-License-Identifier: GPL-3.0-or-later <https://spdx.org/licenses/GPL-3.0-or-later.html>
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "bits.h"
#include "aoc.h"
typedef struct tree {
u16 size;
char *h; /* heigts */
char *v; /* visible (part 1) */
} tree_t;
#define HEIGHT(t, x, y) (((t)->h[((t)->size * (y)) + (x)]))
#define VISIBLE(t, x, y) (((t)->v[((t)->size * (y)) + (x)]))
static tree_t *parse(tree_t *trees)
{
size_t alloc = 0;
char *buf = NULL;
ssize_t buflen;
buflen = getline(&buf, &alloc, stdin);
buf[--buflen] = 0;
trees->size = buflen;
trees->h = malloc((buflen * buflen) * sizeof(char) + 1);
memcpy(trees->h, buf, buflen); /* store first line */
free(buf);
for (buf = trees->h + buflen; ; buf += buflen) {
if (scanf("%s", buf) <= 0)
break;
}
trees->v = calloc(buflen * buflen, sizeof (char));
return trees;
}
static int visible(tree_t *t, int *max, int x, int y)
{
int h = HEIGHT(t, x, y);
if (h > *max) {
VISIBLE(t, x, y) = 1;
if ((*max = h) == '9') {
return 1;
}
}
return 0;
}
static int check_tree(tree_t *t, int x, int y)
{
int i, h = HEIGHT(t, x, y), res = 1, size = t->size, tmp;
for (tmp = 0, i = x + 1; i < size ; ++i) { /* east */
tmp++;
if (HEIGHT(t, i, y) >= h)
break;
}
res *= tmp;
for (tmp = 0, i = x - 1; i >= 0; --i) { /* west */
tmp++;
if (HEIGHT(t, i, y) >= h)
break;
}
res *= tmp;
for (tmp = 0, i = y + 1; i < size; ++i) { /* south */
tmp++;
if (HEIGHT(t, x, i) >= h)
break;
}
res *= tmp;
for (tmp = 0, i = y - 1; i >= 0; --i) { /* north */
tmp++;
if (HEIGHT(t, x, i) >= h)
break;
}
res *= tmp;
return res;
}
static int part1(tree_t *t)
{
int x, y, max, res = 0, size = t->size;
for (y = 1; y < size -1; ++y) { /* to east */
if ((max = HEIGHT(t, 0, y)) < '9') {
for (x = 1; x < size -1; ++x) {
if (visible (t, &max, x, y))
break;
}
}
}
for (y = 1; y < size -1; ++y) { /* to west */
if ((max = HEIGHT(t, size - 1, y)) < '9') {
for (x = size - 2; x > 0; --x) {
if (visible (t, &max, x, y)) {
break;
}
}
}
}
for (x = 1; x < size -1; ++x) { /* to south */
if ((max = HEIGHT(t, x, 0)) < '9') {
for (y = 1; y < size -1; ++y) {
if (visible (t, &max, x, y))
break;
}
}
}
for (x = 1; x < size -1; ++x) { /* to north */
if ((max = HEIGHT(t, x, size - 1)) < '9') {
for (y = size - 2; y > 0; --y) {
if (visible (t, &max, x, y))
break;
}
}
}
for (y = 0; y < size; ++y)
for (x = 0; x < size; ++x)
if (VISIBLE(t, x, y))
res++;
return res + size * 4 - 4;
}
static int part2(tree_t *t)
{
int res = 0, tmp, size = t->size;
for (int y = 1; y < size - 1; ++y) {
for (int x = 1; x < size - 1; ++x) {
tmp = check_tree(t, x, y);
if (tmp > res)
res = tmp;
}
}
return res;
}
int main(int ac, char **av)
{
int part = parseargs(ac, av);
tree_t trees;
parse(&trees);
printf("%s: res=%d\n", *av, part == 1? part1(&trees): part2(&trees));
exit(0);
}

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@@ -45,30 +45,30 @@ check_visible() {
part1() {
declare -ig res
local -i x y max c
local -i x y max
for ((y = 1; y < size -1; ++y)); do # left to right
for ((y = 1; y < size -1; ++y)); do # to east
height max 0 "$y"
(( max == 9 )) && continue
for ((x = 1; x < size -1; ++x)); do
check_visible max "$x" "$y" || break
done
done
for ((y = 1; y < size -1; ++y)); do # right to left
for ((y = 1; y < size -1; ++y)); do # to west
height max $((size - 1)) "$y"
(( max == 9 )) && continue
for ((x = size - 2; x > 0; --x)); do
check_visible max "$x" "$y" || break
done
done
for ((x = 1; x < size -1; ++x)); do # top to bottom
for ((x = 1; x < size -1; ++x)); do # to south
height max "$x" 0
(( max == 9 )) && continue
for ((y = 1; y < size -1; ++y)); do
check_visible max "$x" "$y" || break
done
done
for ((x = 1; x < size -1; ++x)); do # bottom to top
for ((x = 1; x < size -1; ++x)); do # to north
height max "$x" $((size - 1))
(( max == 9 )) && continue
for ((y = size - 2; y > 0; --y)); do