Ural 1519 Formula 1 (DP)

#pragma comment(linker, "/STACK:1024000000,1024000000")

#include <cstdio>

#include <string>

#include <cstdlib>

#include <cmath>

#include <iostream>

#include <cstring>

#include <set>

#include <queue>

#include <algorithm>

#include <vector>

#include <map>

#include <cctype>

#include <cmath>

#include <stack>

#include <sstream>

#include <list>

#include <assert.h>

#include <bitset>

#define debug() puts("++++");

#define gcd(a, b) __gcd(a, b)

#define lson l,m,rt<<1

#define rson m+1,r,rt<<1|1

#define fi first

#define se second

#define pb push_back

#define sqr(x) ((x)*(x))

#define ms(a,b) memset(a, b, sizeof a)

//#define sz size()

#define pu push_up

#define pd push_down

#define cl clear()

#define all 1,n,1

#define FOR(i,x,n)  for(int i = (x); i < (n); ++i)

#define freopenr freopen("in.txt", "r", stdin)

#define freopenw freopen("out.txt", "w", stdout)

using namespace std;

typedef long long LL;

typedef unsigned long long ULL;

typedef pair<int, int> P;

const int INF = 0x3f3f3f3f;

const double inf = 1e20;

const double PI = acos(-1.0);

const double eps = 1e-8;

const int maxn = 10 + 10;

const int maxm = 1e6 + 10;

const int mod = 50007;

const int dr[] = {-1, 0, 1, 0};

const int dc[] = {0, -1, 0, 1};

const char *de[] = {"0000", "0001", "0010", "0011", "0100", "0101", "0110", "0111", "1000", "1001", "1010", "1011", "1100", "1101", "1110", "1111"};

int n, m;

const int mon[] = {0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

const int monn[] = {0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

inline bool is_in(int r, int c) {

  return r >= 0 && r < n && c >= 0 && c < m;

}

struct Hash{

  int head[mod], next[maxm], sz;

  LL f[maxm], state[maxm];

  void clear(){ sz = 0;  ms(head, -1); }

  void push(LL st, LL ans){

    int h = st % mod;

    for(int i = head[h]; ~i; i = next[i])

      if(st == state[i]){

        f[i] += ans;

        return ;

      }

    state[sz] = st;

    f[sz] = ans;

    next[sz] =  head[h];

    head[h] = sz++;

  }

};

Hash dp[2];

int a[maxn][maxn], ch[maxn], code[maxn];

char s[maxn];

int tx, ty;

void decode(int m, LL st){

  for(int i = m; i >= 0; --i){

    code[i] = st & 7;

    st >>= 3;

  }

}

LL encode(int m){

  int cnt = 1;  ms(ch, -1);

  LL st = 0;  ch[0] = 0;

  for(int i = 0; i <= m; ++i){

    if(ch[code[i]] == -1)  ch[code[i]] = cnt++;

    code[i] = ch[code[i]];

    st <<= 3;

    st |= code[i];

  }

  return st;

}

void shift(int m){

  for(int i = m; i; --i)  code[i] = code[i-1];

  code[0] = 0;

}

void dpblank(int i, int j, int cur){

  for(int k = 0; k < dp[cur].sz; ++k){

    decode(m, dp[cur].state[k]);

    int left = code[j-1];

    int up = code[j];

    if(up && left){

      if(up == left){  // last grid

        if(i != tx || j != ty)  continue;

        code[j] = code[j-1] = 0;

        if(j == m)  shift(m);

        dp[cur^1].push(encode(m), dp[cur].f[k]);

      }

      else{  //union two

        code[j] = code[j-1] = 0;

        for(int i = 0; i <= m; ++i)

          if(code[i] == up)  code[i] = left;

        if(j == m)  shift(m);

        dp[cur^1].push(encode(m), dp[cur].f[k]);

      }

    }

    else if(up || left){

      int t = max(up, left);  // 0 or not

      if(a[i][j+1]){

        code[j-1] = 0;

        code[j] = t;

        dp[cur^1].push(encode(m), dp[cur].f[k]);

      }

      if(a[i+1][j]){

        code[j-1] = t;

        code[j] = 0;

        if(j == m)  shift(m);

        dp[cur^1].push(encode(m), dp[cur].f[k]);

      }

    }

    else{  // product two

      if(a[i][j+1] && a[i+1][j]){

        code[j] = code[j-1] = 13;

        dp[cur^1].push(encode(m), dp[cur].f[k]);

      }

    }

  }

}

void dpblock(int i, int j, int cur){

  for(int k = 0; k < dp[cur].sz; ++k){

    decode(m, dp[cur].state[k]);

    code[j] = code[j-1] = 0;

    if(j == m)  shift(m);

    dp[cur^1].push(encode(m), dp[cur].f[k]);

  }

}

int main(){

  scanf("%d %d", &n, &m);

  for(int i = 1; i <= n; ++i){

    scanf("%s", s + 1);

    for(int j = 1; j <= m; ++j)

      if(s[j] == '.'){

        tx = i;  ty = j;

        a[i][j] = 1;

      }

  }

  if(tx == 0){ puts("0");  return 0; }

  int cur = 0;

  dp[cur].cl;  dp[cur].push(0, 1);

  for(int i = 1; i <= n; ++i)

    for(int j = 1; j <= m; ++j){

      dp[cur^1].cl;

      if(a[i][j])  dpblank(i, j, cur);

      else  dpblock(i, j, cur);

      cur ^= 1;

    }

  LL ans = 0;

  for(int i = 0; i < dp[cur].sz; ++i)

    ans += dp[cur].f[i];

  printf("%I64d\n", ans);

  return 0;

}