[ural1519]Formula 1 && 插头DP

#include<cstdio>
#include<algorithm>
#include<cstring>
#include<iostream>
#include<queue>
#define SF scanf
#define PF printf
#define bit(x) (1<<(x))
#define update dp[cur].push(encode() >> 3*(j==m) , dp[cur^1].f[k])
using namespace std;
typedef long long LL;
const int MAXNODE = 1000000;
const int MAXN = 12;
const int MOD = 233333;
struct Hash {
	int sz, adj[MOD+1], next[MAXNODE+10];
	LL state[MAXNODE+10], f[MAXNODE+10];
	void clr() { sz = 0; memset(adj, -1, sizeof(adj)); }
	int push(LL s, LL val) {
		int u = s % MOD;
		for(int i = adj[u]; ~i; i = next[i]) 
			if(state[i] == s)
				return f[i] += val;
		state[sz] = s; f[sz] = val;
		next[sz] = adj[u]; adj[u] = sz++;
		return f[sz-1];
	}
} dp[2];
int n, m, M[MAXN+10][MAXN+10], ex, ey, cur;
int a[MAXN+10], num[MAXN+10];
void decode(LL s) {
	for(int i = m; i >= 0; i--) a[i] = s & 7, s >>= 3;
}
LL encode() {
	memset(num, 0, sizeof(num));
	int k = 0;
	LL ret = 0;
	for(int i = 0; i <= m; i++) {
		if(!num[a[i]] && a[i]) num[a[i]] = ++k;
		ret = (ret << 3) | num[a[i]];
	}
	return ret;
}
void change(int x, int y) {
	for(int i = 0; i <= m; i++) if(a[i] == x) a[i] = y;
}
void dpblank(int i, int j) {
	for(int k = 0; k < dp[cur^1].sz; k++) {
		decode(dp[cur^1].state[k]);
		int &L = a[j-1], &U = a[j];
		if(L && U) {
			if(L == U) {
				if(i == ex && j == ey) {
					L = U = 0;
					update;
				}
			}
			else {
				change(L, U); L = U = 0;
				update;
			}
		}
		else if(L) {
			if(M[i+1][j]) dp[cur].push(dp[cur^1].state[k] >> 3 * (j==m), dp[cur^1].f[k]);
            if(M[i][j+1]) {
                U = L; L = 0;
                update;
            }
        }
		else if(U) {
			if(M[i][j+1]) dp[cur].push(dp[cur^1].state[k] >> 3 * (j==m), dp[cur^1].f[k]);
			if(M[i+1][j]) {
				L = U; U = 0;
				update;
			}
		}
		else {
			if(M[i][j+1] && M[i+1][j]) {
				L = U = m+1;
				update;
			}
		}
	}
}
void dpblock(int i, int j) {
	for(int k = 0; k < dp[cur^1].sz; k++)
		dp[cur].push(dp[cur^1].state[k] >> (3 * (j == m)), dp[cur^1].f[k]);
} 
int main() {
	char ch;
	SF("%d%d", &n, &m);
	for(int i = 1; i <= n; i++)
		for(int j = 1; j <= m; j++) {
			SF(" %c", &ch);
			if(ch == '.') M[ex = i][ey = j] = 1;
			else M[i][j] = 0;
		}
	dp[0].clr(); dp[0].push(0, 1);
	for(int i = 1; i <= n; i++)
		for(int j = 1; j <= m; j++) {
			cur ^= 1; dp[cur].clr();
			if(M[i][j]) dpblank(i, j);
			else dpblock(i, j);
		}
	LL ans = 0;
	for(int i = 0; i < dp[cur^1].sz; i++) ans += dp[cur^1].f[i];
	cout << ans;
}