17/one.c

   1 #include <stdio.h>
   2 #include <stdint.h>
   3 #include <stdbool.h>
   4 #include <stdlib.h>
   5 #include <string.h>
   6
   7 enum cellstatus {active, inactive};
   8
   9 //char *inp[] = {".#.","..#","###"};
  10 char *inp[] =
  11         {"...#.#.#"
  12         ,"..#..#.."
  13         ,"#.#.##.#"
  14         ,"###.##.."
  15         ,"#####.##"
  16         ,"#......."
  17         ,"#..#..##"
  18         ,"...##.##"
  19         };
  20
  21 int steps = 6;
  22 uint16_t *map = NULL;
  23 int xmax, ymax, zmax;
  24
  25 #define mapel(x, y, z) map[(z)*ymax*xmax+(y)*xmax+(x)]
  26
  27 enum cellstatus oldstatus(int x, int y, int z)
  28 {
  29         if(x<0 || y<0 || z<0 || x >= xmax || y >= ymax || z >= zmax)
  30                 return inactive;
  31         return (enum cellstatus)((mapel(x, y, z) >> 8) & 0xff);
  32 }
  33
  34 enum cellstatus newstatus(int x, int y, int z)
  35 {
  36         if(x<0 || y<0 || z<0 || x >= xmax || y >= ymax || z >= zmax)
  37                 return inactive;
  38         return (enum cellstatus)(mapel(x, y, z) & 0xff);
  39 }
  40
  41 void step()
  42 {
  43         //Move the old to the leftmost byte
  44         for (int z = 0; z<zmax; z++)
  45                 for (int y = 0; y<ymax; y++)
  46                         for (int x = 0; x<xmax; x++)
  47                                 mapel(x, y, z) <<= 8;
  48         //Do a step
  49         for (int z = 0; z<zmax; z++) {
  50                 for (int y = 0; y<ymax; y++) {
  51                         for (int x = 0; x<xmax; x++) {
  52                                 int count = 0;
  53                                 for (int dz = -1; dz<=1; dz++) {
  54                                         for (int dy = -1; dy<=1; dy++) {
  55                                                 for (int dx = -1; dx<=1; dx++) {
  56                                                         if (dx == 0 && dy == 0 && dz == 0)
  57                                                                 continue;
  58                                                         if (oldstatus(x+dx, y+dy, z+dz) == active)
  59                                                                 count++;
  60                                                 }
  61                                         }
  62                                 }
  63 //                              fprintf(stderr, "x=%u, y=%u, z=%u, count: %u\n", x, y, z, count);
  64                                 switch (oldstatus(x, y, z)) {
  65                                 case active:
  66                                         mapel(x, y, z)
  67                                                 |= count == 2 || count == 3
  68                                                 ?  active : inactive;
  69                                         break;
  70                                 case inactive:
  71                                         mapel(x, y, z)
  72                                                 |= count == 3
  73                                                 ?  active : inactive;
  74                                         break;
  75                                 }
  76                         }
  77                 }
  78         }
  79 }
  80
  81 int main()
  82 {
  83         //Determine dimensions
  84         int xorig = strlen(inp[0]);
  85         int yorig = sizeof(inp)/sizeof(char *);
  86         xmax = xorig+steps*2;
  87         ymax = yorig+steps*2;
  88         zmax = 1+steps*2;
  89
  90         fprintf(stderr, "Total size: %ux%ux%u, %u elements, %u steps\n",
  91                 xmax, ymax, zmax, xmax*ymax*zmax, steps);
  92         map = malloc(sizeof(uint16_t)*xmax*ymax*zmax);
  93
  94         //Init initially
  95         for(int z = 0; z<zmax; z++)
  96                 for(int y = 0; y<ymax; y++)
  97                         for(int x = 0; x<xmax; x++)
  98                                 mapel(x, y, z) = inactive;
  99         for(int y = 0; y<yorig; y++)
 100                 for(int x = 0; x<xorig; x++) {
 101                         mapel(x+steps, y+steps, steps) =
 102                                 inp[y][x] == '#' ? active : inactive;
 103                 }
 104
 105         for(int i = 0; i<steps; i++) {
 106                 fprintf(stderr, "step: %d\n", i);
 107                 step(map);
 108         }
 109
 110         int count = 0;
 111         for(int z = 0; z<zmax; z++)
 112                 for(int y = 0; y<ymax; y++)
 113                         for(int x = 0; x<xmax; x++)
 114                                 if (newstatus(x, y, z) == active)
 115                                         count++;
 116
 117         printf("%d\n", count);
 118
 119         return 0;
 120 }