day 12 part two wrong, day 13 done

diff --git a/12.txt b/12.txt
new file mode 100644 (file)
index 0000000..731cd4b
--- /dev/null
+++ b/12.txt
@@ -0,0 +1,22 @@
+GC-zi
+end-zv
+lk-ca
+lk-zi
+GC-ky
+zi-ca
+end-FU
+iv-FU
+lk-iv
+lk-FU
+GC-end
+ca-zv
+lk-GC
+GC-zv
+start-iv
+zv-QQ
+ca-GC
+ca-FU
+iv-ca
+start-lk
+zv-FU
+start-zi

diff --git a/12a.c b/12a.c
new file mode 100644 (file)
index 0000000..6232689
--- /dev/null
+++ b/12a.c
@@ -0,0 +1,86 @@
+#include <stdio.h>
+#include <ctype.h>
+
+#include <uthash.h>
+
+struct conn {
+       char key[10];
+       struct node *node;
+       UT_hash_handle hh;
+};
+struct node {
+       char key[10];
+       struct conn *connections;
+       UT_hash_handle hh;
+};
+
+struct node *get_or_create(struct node **graph, char name[])
+{
+       struct node *n;
+       HASH_FIND_STR(*graph, name, n);
+       if (n) {
+               return n;
+       } else {
+               n = malloc(sizeof(struct node));
+               strcpy(n->key, name);
+               n->connections = NULL;
+               HASH_ADD_STR(*graph, key, n);
+       }
+       return n;
+}
+
+void add_connection(struct node *from, struct node *to)
+{
+       //to
+       struct conn *c = malloc(sizeof(struct conn));
+       strcpy(c->key, to->key);
+       c->node = to;
+       HASH_ADD_STR(from->connections, key, c);
+       //fro
+       c = malloc(sizeof(struct conn));
+       strcpy(c->key, from->key);
+       c->node = from;
+       HASH_ADD_STR(to->connections, key, c);
+}
+
+char **copy_visited(char **visited, int nvisited)
+{
+       char **r = malloc(sizeof(char *)*nvisited);
+       memcpy(r, visited, sizeof(char *)*nvisited);
+       return r;
+}
+
+int find_end(struct node *node, char **visited, int nvisited)
+{
+       if (strcmp(node->key, "end") == 0)
+               return 1;
+       if (islower(node->key[0])) {
+               for (int i = 0; i<nvisited; i++)
+                       if (strcmp(node->key, visited[i]) == 0)
+                               return 0;
+               visited = realloc(visited, sizeof(char *)*(nvisited+1));
+               visited[nvisited++] = node->key;
+       }
+       int r = 0;
+       for (struct conn *c = node->connections; c != NULL; c = c->hh.next)
+               r += find_end(c->node, copy_visited(visited, nvisited), nvisited);
+       free(visited);
+       return r;
+}
+
+int main()
+{
+       struct node *graph = NULL;
+       char *buf = NULL;
+       size_t len = 0;
+       while (getline(&buf, &len, stdin) != -1) {
+               char *toname = strchr(buf, '-');
+               *(toname++)= '\0';
+               if (toname[strlen(toname)-1] == '\n')
+                       toname[strlen(toname)-1] = '\0';
+               add_connection(get_or_create(&graph, buf),
+                              get_or_create(&graph, toname));
+       }
+
+       printf("%d\n", find_end(get_or_create(&graph, "start"), NULL, 0));
+}

diff --git a/12b.c b/12b.c
new file mode 100644 (file)
index 0000000..5be7962
--- /dev/null
+++ b/12b.c
@@ -0,0 +1,90 @@
+#include <stdio.h>
+#include <ctype.h>
+#include <stdbool.h>
+
+#include <uthash.h>
+
+struct conn {
+       char key[10];
+       struct node *node;
+       UT_hash_handle hh;
+};
+struct node {
+       char key[10];
+       struct conn *connections;
+       UT_hash_handle hh;
+};
+
+struct node *get_or_create(struct node **graph, char name[])
+{
+       struct node *n;
+       HASH_FIND_STR(*graph, name, n);
+       if (n) {
+               return n;
+       } else {
+               n = malloc(sizeof(struct node));
+               strcpy(n->key, name);
+               n->connections = NULL;
+               HASH_ADD_STR(*graph, key, n);
+       }
+       return n;
+}
+
+void add_connection(struct node *from, struct node *to)
+{
+       //to
+       struct conn *c = malloc(sizeof(struct conn));
+       strcpy(c->key, to->key);
+       c->node = to;
+       HASH_ADD_STR(from->connections, key, c);
+       //fro
+       c = malloc(sizeof(struct conn));
+       strcpy(c->key, from->key);
+       c->node = from;
+       HASH_ADD_STR(to->connections, key, c);
+}
+
+char **copy_visited(char **visited, int nvisited)
+{
+       char **r = malloc(sizeof(char *)*nvisited);
+       memcpy(r, visited, sizeof(char *)*nvisited);
+       return r;
+}
+
+int find_end(struct node *node, char **visited, int nvisited, bool twice)
+{
+       if (strcmp(node->key, "end") == 0)
+               return 1;
+       if (islower(node->key[0])) {
+               for (int i = 0; i<nvisited; i++)
+                       if (strcmp(node->key, visited[i]) == 0)
+                               return 0;
+               visited = realloc(visited, sizeof(char *)*(nvisited+1));
+               visited[nvisited++] = node->key;
+       }
+       int r = 0;
+       for (struct conn *c = node->connections; c != NULL; c = c->hh.next) {
+               if (twice && strcmp(node->key, "start") != 0 && islower(node->key[0]))
+                       r += find_end(c->node, copy_visited(visited, nvisited-1), nvisited-1, false);
+               r += find_end(c->node, copy_visited(visited, nvisited), nvisited, twice);
+       }
+       free(visited);
+       return r;
+}
+
+int main()
+{
+       struct node *graph = NULL;
+       char *buf = NULL;
+       size_t len = 0;
+       while (getline(&buf, &len, stdin) != -1) {
+               char *toname = strchr(buf, '-');
+               *(toname++)= '\0';
+               if (toname[strlen(toname)-1] == '\n')
+                       toname[strlen(toname)-1] = '\0';
+               add_connection(get_or_create(&graph, buf),
+                              get_or_create(&graph, toname));
+       }
+
+       printf("%d\n", find_end(get_or_create(&graph, "start"), NULL, 0, true));
+}

diff --git a/12e.txt b/12e.txt
new file mode 100644 (file)
index 0000000..6fd8c41
--- /dev/null
+++ b/12e.txt
@@ -0,0 +1,7 @@
+start-A
+start-b
+A-c
+A-b
+b-d
+A-end
+b-end

diff --git a/12e2.txt b/12e2.txt
new file mode 100644 (file)
index 0000000..62cc714
--- /dev/null
+++ b/12e2.txt
@@ -0,0 +1,10 @@
+dc-end
+HN-start
+start-kj
+dc-start
+dc-HN
+LN-dc
+HN-end
+kj-sa
+kj-HN
+kj-dc

diff --git a/12e3.txt b/12e3.txt
new file mode 100644 (file)
index 0000000..65f3833
--- /dev/null
+++ b/12e3.txt
@@ -0,0 +1,18 @@
+fs-end
+he-DX
+fs-he
+start-DX
+pj-DX
+end-zg
+zg-sl
+zg-pj
+pj-he
+RW-he
+fs-DX
+pj-RW
+zg-RW
+start-pj
+he-WI
+zg-he
+pj-fs
+start-RW

diff --git a/13.txt b/13.txt
new file mode 100644 (file)
index 0000000..556b07a
--- /dev/null
+++ b/13.txt
@@ -0,0 +1,812 @@
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+
+fold along x=655
+fold along y=447
+fold along x=327
+fold along y=223
+fold along x=163
+fold along y=111
+fold along x=81
+fold along y=55
+fold along x=40
+fold along y=27
+fold along y=13
+fold along y=6

diff --git a/13a.c b/13a.c
new file mode 100644 (file)
index 0000000..bd315ce
--- /dev/null
+++ b/13a.c
@@ -0,0 +1,61 @@
+#include <stdio.h>
+#include <stdbool.h>
+
+#include <uthash.h>
+
+struct point { int x; int y; };
+struct dot { struct point p; UT_hash_handle hh; };
+
+#define pnt(px, py) ((struct point){.x=(px), .y=(py)})
+void add_dot(struct dot **grid, struct point p)
+{
+       struct dot *d;
+       HASH_FIND(hh, *grid, &p, sizeof(struct point), d);
+       if (!d) {
+               d = malloc(sizeof(struct dot));
+               d->p = p;
+               HASH_ADD(hh, *grid, p, sizeof(struct point), d);
+       }
+}
+
+#define foldp(p, f) ( (f) - ( (p) - (f) ) )
+
+void fold(struct dot **grid, char axis, int num)
+{
+       struct dot *d, *tmp;
+       HASH_ITER(hh, *grid, d, tmp) {
+               struct point p = d->p;
+               if (axis == 'x' && p.x >= num) {
+                       HASH_DEL(*grid, d);
+                       if (p.x > num)
+                               add_dot(grid, pnt(foldp(p.x, num), p.y));
+               } else if (axis == 'y' && p.y >= num) {
+                       HASH_DEL(*grid, d);
+                       if (p.y > num)
+                               add_dot(grid, pnt(p.x, foldp(p.y, num)));
+               }
+       }
+}
+
+int main()
+{
+       char *buf = NULL;
+       size_t len = 0;
+       struct dot *grid = NULL;
+       bool dots = true;
+
+       while (getline(&buf, &len, stdin) != -1) {
+               if (strcmp(buf, "\n") == 0) {
+                       dots = false;
+               } else if (dots) {
+                       char *to = strchr(buf, ',');
+                       *(to++)= '\0';
+                       add_dot(&grid, pnt(atoi(buf), atoi(to)));
+               } else {
+                       char *to = strchr(buf, '=');
+                       fold (&grid, *(to-1), atoi(to+1));
+                       break;
+               }
+       }
+       printf("%d\n", HASH_COUNT(grid));
+}

diff --git a/13b.c b/13b.c
new file mode 100644 (file)
index 0000000..092cf7a
--- /dev/null
+++ b/13b.c
@@ -0,0 +1,71 @@
+#include <stdio.h>
+#include <stdbool.h>
+
+#include <uthash.h>
+
+struct point { int x; int y; };
+struct dot { struct point p; UT_hash_handle hh; };
+
+#define pnt(px, py) ((struct point){.x=(px), .y=(py)})
+
+void add_dot(struct dot **grid, struct point p)
+{
+       struct dot *d;
+       HASH_FIND(hh, *grid, &p, sizeof(struct point), d);
+       if (!d) {
+               d = malloc(sizeof(struct dot));
+               d->p = p;
+               HASH_ADD(hh, *grid, p, sizeof(struct point), d);
+       }
+}
+
+#define foldp(p, f) ( (f) - ( (p) - (f) ) )
+
+void fold(struct dot **grid, char axis, int num)
+{
+       struct dot *d, *tmp;
+       HASH_ITER(hh, *grid, d, tmp) {
+               struct point p = d->p;
+               if (axis == 'x' && p.x >= num) {
+                       HASH_DEL(*grid, d);
+                       if (p.x > num)
+                               add_dot(grid, pnt(foldp(p.x, num), p.y));
+               } else if (axis == 'y' && p.y >= num) {
+                       HASH_DEL(*grid, d);
+                       if (p.y > num)
+                               add_dot(grid, pnt(p.x, foldp(p.y, num)));
+               }
+       }
+}
+
+int main()
+{
+       char *buf = NULL;
+       size_t len = 0;
+       struct dot *grid = NULL;
+
+       while (getline(&buf, &len, stdin) != -1 && strcmp(buf, "\n") != 0) {
+               char *to = strchr(buf, ',');
+               *(to++)= '\0';
+               add_dot(&grid, pnt(atoi(buf), atoi(to)));
+       }
+       while (getline(&buf, &len, stdin) != -1) {
+               char *to = strchr(buf, '=');
+               fold (&grid, *(to-1), atoi(to+1));
+       }
+
+       int maxx = 0, maxy = 0;
+       for (struct dot *d = grid; d!=NULL; d = d->hh.next) {
+               maxx = maxx < d->p.x ? d->p.x : maxx;
+               maxy = maxy < d->p.y ? d->p.y : maxy;
+       }
+
+       struct dot *d;
+       for (int y = 0; y<=maxy; y++) {
+               for (int x = 0; x<=maxx; x++) {
+                       HASH_FIND(hh, grid, &pnt(x, y), sizeof(struct point), d);
+                       printf("%c", d ? '#' : '.');
+               }
+               printf("\n");
+       }
+}

diff --git a/13e.txt b/13e.txt
new file mode 100644 (file)
index 0000000..282114c
--- /dev/null
+++ b/13e.txt
@@ -0,0 +1,21 @@
+6,10
+0,14
+9,10
+0,3
+10,4
+4,11
+6,0
+6,12
+4,1
+0,13
+10,12
+3,4
+3,0
+8,4
+1,10
+2,14
+8,10
+9,0
+
+fold along y=7
+fold along x=5