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Day 16/part 2: C version.

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This commit is contained in:
Bruno Raoult
2021-01-15 18:40:09 +01:00
parent 2667617088
commit faeb8cf9fb
4 changed files with 250 additions and 10 deletions
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8
day16/Makefile
View File

@@ -15,13 +15,13 @@ output:
compile: ex1-c ex2-c
ex1:
ex1: ex1-c
@$(TIME) ex1.bash < $(INPUT) 2>&1
@$(TIME) ex1-c 2020 < $(INPUT) 2>&1
@$(TIME) ex1-c < $(INPUT) 2>&1
ex2:
ex2: ex2-c
@$(TIME) ex2.bash < $(INPUT) 2>&1
@#$(TIME) ex1-c 30000000 < $(INPUT) 2>&1
@$(TIME) ex2-c < $(INPUT) 2>&1
clean:
@rm -f ex1-c ex2-c core

3
day16/ex1-c.c
View File

@@ -5,9 +5,6 @@
#include <stdlib.h>
#include <string.h>
#define AA "ABCD"
#define LAA sizeof(AA)
/* tickets ranges */
struct srange {
char *name;

6
day16/ex1.bash
View File

@@ -5,7 +5,7 @@
CMD=${0##*/}
#shopt -s extglob
declare -A valid=()
declare -A VALID=()
declare -i state=0 res=0
while read -r line; do
@@ -13,7 +13,7 @@ while read -r line; do
n1=$(seq "${BASH_REMATCH[2]}" "${BASH_REMATCH[3]}")
n2=$(seq "${BASH_REMATCH[5]}" "${BASH_REMATCH[6]}")
for i in $n1 $n2; do
valid[$i]=1
VALID[$i]=1
done
elif [[ $line =~ (your ticket:|nearby tickets) ]]; then
((state++))
@@ -21,7 +21,7 @@ while read -r line; do
if ((state == 2)); then
for i in ${line//,/ }; do
# shellcheck disable=SC2100
[[ ! -v valid[$i] ]] && res=res+i
[[ ! -v VALID[$i] ]] && res=res+i
done
fi
fi

243
day16/ex2-c.c Normal file
View File

@@ -0,0 +1,243 @@
/* ex1-c: Advent2020 game, day 16/game 1
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
/* tickets ranges */
struct srange {
char *name;
int s1, e1;
int s2, e2;
int col;
int possiblecount;
int *possible; /* possible[i]=-1 => column i cannot be */
};
struct list {
int size;
int last;
struct srange *ranges;
} list = {
0, 0, NULL
};
#define BLOCKSIZE 1024 /* number of elements for realloc() */
int *myticket=NULL;
int *curticket=NULL; /* current ticket */
int ticketsize=0;
void print_ranges()
{
unsigned i, n=list.last;
int j;
struct srange *p=list.ranges;
printf("RANGES: address=%p last=%u size=%u\n", list.ranges, n, list.size);
for (i=0; i<n; ++i, ++p) {
printf(" [%03u] %u-%u %u-%u [%s]\n", i, p->s1, p->e1, p->s2, p->e2, p->name);
printf(" Possible cols (%d remaining) : ", p->possiblecount);
for (j=0; j<ticketsize; ++j)
if (p->possible[j] >= 0)
printf(" %d", p->possible[j]);
putchar('\n');
}
}
struct srange *add_range(name, s1, e1, s2, e2)
char *name;
int s1, e1, s2, e2;
{
struct srange *p;
if (list.last == list.size) {
list.ranges=realloc(list.ranges, sizeof(struct srange)*BLOCKSIZE);
list.size+=BLOCKSIZE;
}
p=list.ranges+list.last;
p->name=strdup(name);
p->s1=s1;
p->e1=e1;
p->s2=s2;
p->e2=e2;
p->col=-1;
list.last++;
return p;
}
void print_ticket(ticket)
int *ticket;
{
int i;
printf("Ticket: ");
for (i=0; i<ticketsize; ++i)
printf("%d ", *(ticket+i));
putchar('\n');
}
int *parse_ticket(str)
char *str;
{
int i;
char *p;
if (!curticket)
curticket=malloc(ticketsize * sizeof *myticket);
for (i=0, p=str; i<ticketsize; ++i, ++p)
curticket[i]=(int)strtol(p, &p, 10);
return curticket;
}
int *parse_myticket(str)
char *str;
{
int i, j, *possible;
char *p;
ticketsize=1;
for (p=str; *p; p++)
if (*p==',')
ticketsize++;
myticket=malloc(ticketsize * sizeof *myticket);
for (p=str, i=0; i<ticketsize; ++i, ++p)
myticket[i]=(int)strtol(p, &p, 10);
// set possible columns for all ranges
for (i=0; i<list.last; ++i) {
possible=malloc(sizeof (int) * ticketsize);
list.ranges[i].possible=possible;
list.ranges[i].possiblecount=ticketsize;
for (j=0; j<ticketsize; ++j)
possible[j]=j;
}
return myticket;
}
int is_in_range(i, range)
int i;
struct srange *range;
{
if ((i>=range->s1 && i<=range->e1) || (i>=range->s2 && i<=range->e2))
return 1;
else
return 0;
}
int check_valid(ticket)
int *ticket;
{
int i, r, found;
for (i=0; i<ticketsize; ++i) {
found=0;
for (r=0; r<list.last; ++r) {
if (is_in_range(*(ticket+i), list.ranges+r)) {
found=1;
break;
}
}
if (!found)
break;
}
return found;
}
void ex2_add(ticket)
int *ticket;
{
int i, r;
if (check_valid(ticket)) {
for (i=0; i<ticketsize; ++i) {
for (r=0; r<list.last; ++r) {
if (!is_in_range(*(ticket+i), list.ranges+r)) {
// this value cannot be in this range, we unset this column
list.ranges[r].possible[i]=-1;
list.ranges[r].possiblecount--;
}
}
}
}
}
unsigned long ex2()
{
int i, r, r1, unique=0;
unsigned long res=1;
struct srange *range, *range1;
while (!unique) {
unique=1;
for (r=0; r<list.last; ++r) {
range=list.ranges+r;
if (range->col >= 0)
continue;
if (range->possiblecount == 1) {
for (i=0; range->possible[i]==-1 && i<ticketsize; ++i)
;
range->col=i;
for (r1=0; r1<list.last; ++r1) {
range1=list.ranges+r1;
if (range1 != range && range1->possible[i] != -1) {
range1->possible[i]=-1;
range1->possiblecount--;
unique=0;
}
}
break;
}
}
}
for (r=0; r<list.last; ++r) {
range=list.ranges+r;
if (!strncmp(range->name, "departure", 9)) {
res*=myticket[range->col];
}
}
return res;
}
int main(ac, av)
int ac;
char **av;
{
char line[1024], pname[80], *elabel;
int s1, e1, s2, e2, end=0, status=0;
unsigned long res=0;
int *ticket;
while (fgets(line, sizeof line, stdin)) {
if (*line=='\n')
continue;
if (*line >= '0' && *line <= '9') {
switch (status) {
case 1:
ticket=parse_myticket(line);
// print_ranges();
break;
case 2:
ticket=parse_ticket(line);
// valid ticket
// print_ticket(ticket);
ex2_add(ticket);
break;
}
continue;
}
if (elabel=strchr(line, ':')) {
if (*(elabel+1)=='\n') {
status++;
continue;
}
sscanf(line, "%[^:]: %d-%d or %d-%d %n",
pname, &s1, &e1, &s2, &e2, &end);
add_range(pname, s1, e1, s2, e2);
}
}
res=ex2();
printf("%s : res=%lu\n", *av, res);
exit (0);
}