11a.c

   1 #include <stdio.h>
   2
   3 void flash(char grid[10][10], int *flashes, int x, int y)
   4 {
   5         //already flashed or not charged up enough
   6         if (grid[y][x] == 0 || grid[y][x] < 10)
   7                 return;
   8         (*flashes)++;
   9         grid[y][x] = 0;
  10         for (int dy = -1; dy<=1; dy++)
  11                 for (int dx = -1; dx<=1; dx++)
  12                         if ( (dx != 0 || dy != 0) &&
  13                                         x+dx >= 0 && x+dx < 10 &&
  14                                         y+dy >= 0 && y+dy < 10) {
  15                                 if (grid[y+dy][x+dx] != 0)
  16                                         grid[y+dy][x+dx]++;
  17                                 flash(grid, flashes, x+dx, y+dy);
  18                         }
  19 }
  20
  21 int main()
  22 {
  23         int x = 0, y = 0;
  24         int c;
  25         char grid[10][10];
  26         while( (c = getchar()) != EOF) {
  27                 if (c == '\n') {
  28                         y++;
  29                         x = 0;
  30                 } else {
  31                         grid[y][x++] = c-'0';
  32                 }
  33         }
  34
  35         int flashes = 0;
  36         for (int i = 0; i<100; i++) {
  37                 for (int y = 0; y<10; y++)
  38                         for (int x = 0; x<10; x++)
  39                                 grid[y][x]++;
  40                 for (int y = 0; y<10; y++)
  41                         for (int x = 0; x<10; x++)
  42                                 flash(grid, &flashes, x, y);
  43         }
  44
  45         printf("%d\n", flashes);
  46 }