Sicily 1171. The Game of Efil

// DFS
#include <iostream>
#include <cstdio>
#include <cstring>

using namespace std;

int m, n;
int res;
int dx[8] = { -1, -1, 0, 1, 1, 1, 0, -1 };
int dy[8] = { 0, 1, 1, 1, 0, -1, -1, -1 };
int d[16][16], tar[16][16];

void cal() {
int around, _new;
for (int i = 0; i < m; i++)
for (int j = 0; j < n; j++) {
around = 0;
for (int k = 0; k < 8; k++)
// 省去对越界的判断
if (d[(i + dx[k] + m) % m][(j + dy[k] + n) % n])
around++;

if (around == 3)
_new = 1;
else if (d[i][j] == 1 && around == 2)
_new = 1;
else
_new = 0;

// 生成一个格子判断一下
if (tar[i][j] != _new)
return;
}

res++;
return;
}

void dfs(int x, int y) {
if (x == m) {
cal();
return;
}

// 利用DFS遍历状态
d[x][y] = 0;
if (y == n - 1)
dfs(x + 1, 0);
else
dfs(x, y + 1);
d[x][y] = 1;
if (y == n - 1)
dfs(x + 1, 0);
else
dfs(x, y + 1);
}

int main(int argc, char **argv) {
int C = 1;
while (cin >> m >> n && (m | n)) {
memset(tar, 0, sizeof(tar));

int k;
scanf("%d", &k);

int x, y;
for (int i = 0; i < k; ++i) {
scanf("%d%d", &x, &y);
tar[x][y] = 1;
}

res = 0;
dfs(0, 0);

if (res)
printf("Case %d: %d possible ancestors.\n", C++, res);
else
printf("Case %d: Garden of Eden.\n", C++);
}
return 0;
}