add day 21
authorMart Lubbers <mart@martlubbers.net>
Tue, 21 Dec 2021 09:52:09 +0000 (10:52 +0100)
committerMart Lubbers <mart@martlubbers.net>
Tue, 21 Dec 2021 09:52:09 +0000 (10:52 +0100)
19.txt [new file with mode: 0644]
19a.c [new file with mode: 0644]
19e.txt [new file with mode: 0644]
21.txt [new file with mode: 0644]
21a.c [new file with mode: 0644]
21b.c [new file with mode: 0644]
21e.txt [new file with mode: 0644]
Makefile

diff --git a/19.txt b/19.txt
new file mode 100644 (file)
index 0000000..4dec4fb
--- /dev/null
+++ b/19.txt
@@ -0,0 +1,717 @@
+--- scanner 0 ---
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+
+--- scanner 1 ---
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+
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+
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+
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+
+--- scanner 7 ---
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+--- scanner 10 ---
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+--- scanner 11 ---
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+
+--- scanner 12 ---
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+
+--- scanner 13 ---
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+
+--- scanner 14 ---
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+
+--- scanner 15 ---
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+
+--- scanner 16 ---
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+
+--- scanner 17 ---
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+
+--- scanner 18 ---
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+--- scanner 19 ---
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+--- scanner 20 ---
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+
+--- scanner 21 ---
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+--- scanner 22 ---
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+
+--- scanner 23 ---
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+
+--- scanner 24 ---
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+
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diff --git a/19a.c b/19a.c
new file mode 100644 (file)
index 0000000..e468798
--- /dev/null
+++ b/19a.c
@@ -0,0 +1,88 @@
+#include <stdio.h>
+#include <stdbool.h>
+#include <string.h>
+
+struct point {int x; int y; int z; };
+struct scanner {
+       int num;
+       int npoints;
+       struct point points[100];
+};
+
+bool parse_scanner(struct scanner *s)
+{
+       char *b = NULL;
+       size_t len;
+       if (-1 == getline(&b, &len, stdin))
+               return false;
+       sscanf(b, "--- scanner %d ---\n", &s->num);
+       while (getline(&b, &len, stdin) != -1 && strcmp(b, "\n") != 0) {
+               sscanf(b, "%d,%d,%d\n"
+                       , &s->points[s->npoints].x
+                       , &s->points[s->npoints].y
+                       , &s->points[s->npoints].z);
+               s->npoints++;
+       }
+       return true;
+}
+
+struct point orient(struct point p, struct point r, int orientation)
+{
+       if (orientation == 0)
+               return (struct point){.x=r.x*p.x, .y=r.y*p.y, .z=r.z*p.z};
+       else if (orientation == 1)
+               return (struct point){.x=r.x*p.x, .y=r.y*p.z, .z=r.z*p.y};
+       else if (orientation == 2)
+               return (struct point){.x=r.x*p.y, .y=r.y*p.x, .z=r.z*p.z};
+       else if (orientation == 3)
+               return (struct point){.x=r.x*p.y, .y=r.y*p.z, .z=r.z*p.x};
+       else if (orientation == 4)
+               return (struct point){.x=r.x*p.z, .y=r.y*p.x, .z=r.z*p.y};
+       else if (orientation == 5)
+               return (struct point){.x=r.x*p.z, .y=r.y*p.y, .z=r.z*p.x};
+       else
+               fprintf(stderr, "unknown orientation\n");
+}
+struct point rotations[] =
+       { {-1, -1, -1}
+       , {-1, -1,  1}
+       , {-1,  1, -1}
+       , {-1,  1,  1}
+       , { 1, -1, -1}
+       , { 1, -1,  1}
+       , { 1,  1, -1}
+       , { 1,  1,  1}
+       };
+
+void match_scanners(struct scanner *l, struct scanner *r, int rot, int or)
+{
+       for (int dx = -1000; dx<1000; dx++) {
+               for (int dy = -1000; dy<1000; dy++) {
+                       for (int dz = -1000; dz<1000; dz++) {
+                               
+
+                       }
+               }
+       }
+}
+
+int main()
+{
+       int nscanner = 0;
+       struct scanner scanners[25];
+       while(parse_scanner(&scanners[nscanner]))
+               nscanner++;
+
+       for (int i = 0; i<nscanner; i++) {
+               for (int j = 0; j<nscanner; j++) {
+                       if (i == j)
+                               continue;
+                       for (int rot = 0; rot<8; rot++) {
+                               for (int or = 0; or<6; or++) {
+                                       match_scanners(&scanners[i], &scanners[j], rot, or);
+                               }
+                       }
+               }
+       }
+
+}
diff --git a/19e.txt b/19e.txt
new file mode 100644 (file)
index 0000000..4e496e9
--- /dev/null
+++ b/19e.txt
@@ -0,0 +1,136 @@
+--- scanner 0 ---
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+7,-33,-71
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+
+--- scanner 1 ---
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+
+--- scanner 2 ---
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+
+--- scanner 3 ---
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+
+--- scanner 4 ---
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diff --git a/21.txt b/21.txt
new file mode 100644 (file)
index 0000000..f551232
--- /dev/null
+++ b/21.txt
@@ -0,0 +1,2 @@
+Player 1 starting position: 5
+Player 2 starting position: 6
diff --git a/21a.c b/21a.c
new file mode 100644 (file)
index 0000000..fa54a2e
--- /dev/null
+++ b/21a.c
@@ -0,0 +1,28 @@
+#include <stdio.h>
+
+void move (int roll, int *p, int *score)
+{
+       *p = (*p+roll*9+6)%10;
+       if (*p == 0)
+               *p = 10;
+       *score += *p;
+}
+
+int main()
+{
+       int p1, p2, p1score = 0, p2score = 0;
+       if (2 != scanf(
+                       "Player 1 starting position: %d\n"
+                       "Player 2 starting position: %d\n", &p1, &p2))
+               return 1;
+
+       int roll = 0;
+       while (p1score < 1000 && p2score < 1000) {
+               if (roll%2==0)
+                       move(roll, &p1, &p1score);
+               else
+                       move(roll, &p2, &p2score);
+               roll++;
+       }
+       printf("%d\n", (roll%2==0 ? p1score : p2score)*roll*3);
+}
diff --git a/21b.c b/21b.c
new file mode 100644 (file)
index 0000000..96153cc
--- /dev/null
+++ b/21b.c
@@ -0,0 +1,81 @@
+#include <stdio.h>
+#include <stdbool.h>
+#include <uthash.h>
+#include <limits.h>
+
+struct result { unsigned long p1wins; unsigned long p2wins; };
+struct player { int pos; int score; };
+struct cache {
+       struct key { bool p1turn; struct player p1; struct player p2; } key;
+       struct result res;
+       UT_hash_handle hh;
+};
+
+struct player move (struct player p, int steps)
+{
+       p.pos = (p.pos+steps)%10;
+       if (p.pos == 0)
+               p.pos = 10;
+       p.score += p.pos;
+       return p;
+}
+
+struct cache *cache = NULL;
+
+struct result playd (bool p1turn, struct player p1, struct player p2);
+struct result play(bool p1turn, struct player p1, struct player p2)
+{
+       struct cache *e;
+       struct key p;
+       memset(&p, 0, sizeof(p));
+       p = (struct key){.p1turn=p1turn, .p1=p1, .p2=p2};
+       HASH_FIND(hh, cache, &p, sizeof(struct key), e);
+       if (e == NULL) {
+               struct result r = playd(p1turn, p1, p2);
+               e = calloc(1, sizeof(struct cache));
+               *e = (struct cache){.key=p, .res=r};
+               HASH_ADD(hh, cache, key, sizeof(struct key), e);
+               return r;
+       } else {
+               return e->res;
+       }
+}
+
+void add_result(struct result *l, struct result r)
+{
+       l->p1wins += r.p1wins;
+       l->p2wins += r.p2wins;
+}
+
+struct result playd (bool p1turn, struct player p1, struct player p2)
+{
+       struct result r = {.p1wins=0, .p2wins=0};
+       if (p1.score >= 21) {
+               r.p1wins++;
+       } else if (p2.score >= 21) {
+               r.p2wins++;
+       } else if (p1turn) {
+               for (int i = 1; i<=3; i++)
+                       for (int j = 1; j<=3; j++)
+                               for (int k = 1; k<=3; k++)
+                                       add_result(&r, play(!p1turn, move(p1, i+j+k), p2));
+       } else {
+               for (int i = 1; i<=3; i++)
+                       for (int j = 1; j<=3; j++)
+                               for (int k = 1; k<=3; k++)
+                                       add_result(&r, play(!p1turn, p1, move(p2, i+j+k)));
+       }
+       return r;
+}
+
+int main()
+{
+       struct player p1 = {.score=0}, p2 = {.score=0};
+       if (2 != scanf(
+                       "Player 1 starting position: %d\n"
+                       "Player 2 starting position: %d\n", &p1.pos, &p2.pos))
+               return 1;
+
+       struct result r = play(true, p1, p2);
+       printf("%lu\n", r.p1wins > r.p2wins ? r.p1wins : r.p2wins);
+}
diff --git a/21e.txt b/21e.txt
new file mode 100644 (file)
index 0000000..3f69194
--- /dev/null
+++ b/21e.txt
@@ -0,0 +1,2 @@
+Player 1 starting position: 4
+Player 2 starting position: 8
index b6f6074..b03dbc8 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
 CFLAGS:=-Wall -Wextra -O3
 LFLAGS:=-f
 
-BINARIES:=$(filter-out 19a 19b,$(foreach num,$(shell seq -f '%02.0f' 1 20),$(num)a $(num)b))
+BINARIES:=$(filter-out 19a 19b,$(foreach num,$(shell seq -f '%02.0f' 1 21),$(num)a $(num)b))
 
 all: $(BINARIES)