ZOJ-2412

#include<stdio.h>

static int m, n;
char c[50][50];
static int dir[4][2] = { { -1, 0 }, { 1, 0 }, { 0, -1 }, { 0, 1 } };
static int map[11][4] = { { 0, 2, -1, -1 }, { 0, 3, -1, -1 }, { 1, 2, -1, -1 },
{ 1, 3, -1, -1 }, { 0, 1, -1, -1 }, { 2, 3, -1, -1 },
{ 0, 2, 3, -1 }, { 0, 1, 2, -1 }, { 1, 2, 3, -1 }, {
0, 1, 3, -1 },
{ 0, 1, 2, 3 } };
static int pass[4] = { 1, 0, 3, 2 };

static int can_pass(int dir, char to)
{
int i, *array = map[to - 'A'];
for (i = 0; i < 4 && array[i] != -1; i++)
if (pass[dir] == array[i])
return 1;
return 0;
}

static void dfs(int row, int col)
{
int i, *adjs = map[c[row][col] - 'A'];
c[row][col] = 0;
for (i = 0; i < 4 && adjs[i] != -1; i++)
{
int rr = row + dir[adjs[i]][0];
int cc = col + dir[adjs[i]][1];
if (rr >= 0 && rr < m && cc >= 0 && cc < n && c[rr][cc]
&& can_pass(adjs[i], c[rr][cc]))
dfs(rr, cc);
}
}

int main()
{
while (scanf("%d %d", &m, &n), m >= 0 && n >= 0)
{
getchar();
int i, j;
for (i = 0; i < m; i++)
{
for (j = 0; j < n; j++)
c[i][j] = getchar();
getchar();
}
getchar();

int total = 0;
for (i = 0; i < m; i++)
for (j = 0; j < n; j++)
if (c[i][j])
{
total++;
dfs(i, j);
}
printf("%d\n", total);
}
return 0;
}