add day 21

[advent21.git] / 19a.c

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);
+                               }
+                       }
+               }
+       }
+
+}