1 #include <stdio.h>
   2 #include <string.h>
   3 #include <stdlib.h>
   4 
   5 #define TPS 4
   6 
   7 #define STEP                  \
   8  do {                         \
   9    tt =1;                     \
  10    for(; d<TPS; d++)            \
  11    {                          \
  12        tr=r+tp[d][0], tc=c+tp[d][1];         \
  13        if (tr>=0 && tr <n && tc>=0 && tc <m && p[tr][tc]=='.')    \
  14          {  r = tr, c = tc;   \
  15             p[r][c] = '0'+d;    \
  16             st[t] = d;        \
  17             t++, s++;         \
  18             tt  = 0;           \   
  19             break;             \
  20          }                     \                
  21    }                           \
  22 } while(0)
  23      
  24      
  25 #define  OMAX  25
  26 
  27 void printp(int n, int m, char **p)
  28 {
  29   int i, j;
  30   fprintf(stdout, "\n");
  31   for(i=0; i<n; i++)
  32   {
  33     for(j=0; j<m; j++)
  34       fprintf(stdout, "%c", p[i][j]);
  35     fprintf(stdout, "\n");
  36   }
  37 }
  38 
  39 int count(int n, int m, char **p)
  40 {
  41   int st[OMAX*OMAX];
  42   int s, d;
  43   int tt;
  44   signed int t;
  45   signed int r, c, tr, tc;
  46   int tp[TPS][2] = { {+1, 0}, {-1, 0}, {0, +1}, {0, -1} };
  47   //printp(n,m,p);
  48   for(r=0; r<n; r++)
  49     {
  50       for(c=0; c<m; c++)
  51         if(p[r][c]=='@')
  52           break;
  53       if(p[r][c]=='@')
  54         break;
  55     }
  56   for(s=1, st[0]=TPS, t=1; t>0;)
  57     {
  58       d=0;
  59       STEP;
  60       //fprintf(stderr, "(%d, %d)\t", r, c);
  61       //printp(n,m,p);
  62 
  63       while (t>0 && tt == 1) 
  64         {
  65           t--;
  66           d = st[t];
  67           r -= tp[d][0];
  68           c -= tp[d][1];
  69           d++;
  70           STEP;
  71           //fprintf(stderr, "(%d, %d)\t", r, c);
  72         }
  73     }
  74   return s;
  75 }
  76 
  77 int pp(char **p)
  78 {
  79   int n, m;
  80   int i;
  81   fscanf(stdin, "%d%d", &m, &n);
  82   for(i=0; i<n ;i++)
  83     fscanf(stdin,"%s", p[i]);
  84 
  85   if(n==0 || m==0)
  86     return 0;
  87   else
  88     return count(n, m, p);
  89 }
  90 
  91 int main()
  92 {
  93   int i;
  94   char **p;
  95   p = (char **)malloc(sizeof(char*)*OMAX);
  96   for(i=0; i< OMAX; i++)
  97     p[i]=(char *)malloc(sizeof(char)*OMAX);
  98   do
  99     {
 100       i=pp(p);
 101       if(i!=0)
 102         fprintf(stdout, "%d\n", i);
 103     }
 104   while(i!=0);
 105 
 106   return 0;
 107 }