結果

問題 No.663 セルオートマトンの逆操作
ユーザー はむこ
提出日時 2018-01-30 23:40:08
言語 C++11
(gcc 4.8.5)
結果
AC  
実行時間 5 ms
コード長 6,758 Byte
コンパイル時間 1,450 ms
使用メモリ 1,868 KB
最終ジャッジ日時 2019-06-24 00:24:33

テストケース

テストケース表示
入力 結果 実行時間
使用メモリ
small1.txt AC 2 ms
1,684 KB
small2.txt AC 4 ms
1,688 KB
small3.txt AC 3 ms
1,684 KB
small4.txt AC 2 ms
1,688 KB
small5.txt AC 4 ms
1,684 KB
small6.txt AC 3 ms
1,688 KB
small7.txt AC 4 ms
1,688 KB
small8.txt AC 3 ms
1,684 KB
small9.txt AC 2 ms
1,688 KB
small10.txt AC 3 ms
1,688 KB
small11.txt AC 3 ms
1,684 KB
small12.txt AC 3 ms
1,684 KB
small13.txt AC 2 ms
1,684 KB
small14.txt AC 3 ms
1,688 KB
small15.txt AC 3 ms
1,684 KB
small16.txt AC 3 ms
1,684 KB
test1.txt AC 4 ms
1,696 KB
test2.txt AC 3 ms
1,684 KB
test3.txt AC 4 ms
1,684 KB
test4.txt AC 3 ms
1,688 KB
test5.txt AC 4 ms
1,700 KB
test6.txt AC 3 ms
1,704 KB
test7.txt AC 4 ms
1,732 KB
test8.txt AC 4 ms
1,772 KB
test9.txt AC 5 ms
1,800 KB
test10.txt AC 3 ms
1,848 KB
test11.txt AC 3 ms
1,868 KB
test12.txt AC 3 ms
1,688 KB
test13.txt AC 3 ms
1,688 KB
テストケース一括ダウンロード

ソースコード

diff #
#include <bits/stdc++.h>
#include <sys/time.h>
using namespace std;

#define rep(i,n) for(long long i = 0; i < (long long)(n); i++)
#define repi(i,a,b) for(long long i = (long long)(a); i < (long long)(b); i++)
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define fi first
#define se second
#define mt make_tuple
#define mp make_pair
template<class T1, class T2> bool chmin(T1 &a, T2 b) { return b < a && (a = b, true); }
template<class T1, class T2> bool chmax(T1 &a, T2 b) { return a < b && (a = b, true); }

using ll = long long; using vll = vector<ll>; using vvll = vector<vll>; using P = pair<ll, ll>;
using ld = long double;  using vld = vector<ld>; 
using vi = vector<int>; using vvi = vector<vi>; vll conv(vi& v) { vll r(v.size()); rep(i, v.size()) r[i] = v[i]; return r; }

inline void input(int &v){ v=0;char c=0;int p=1; while(c<'0' || c>'9'){if(c=='-')p=-1;c=getchar();} while(c>='0' && c<='9'){v=(v<<3)+(v<<1)+c-'0';c=getchar();} v*=p; } // これを使うならば、tieとかを消して!!
template <typename T, typename U> ostream &operator<<(ostream &o, const pair<T, U> &v) {  o << "(" << v.first << ", " << v.second << ")"; return o; }
template<size_t...> struct seq{}; template<size_t N, size_t... Is> struct gen_seq : gen_seq<N-1, N-1, Is...>{}; template<size_t... Is> struct gen_seq<0, Is...> : seq<Is...>{};
template<class Ch, class Tr, class Tuple, size_t... Is>
void print_tuple(basic_ostream<Ch,Tr>& os, Tuple const& t, seq<Is...>){ using s = int[]; (void)s{0, (void(os << (Is == 0? "" : ", ") << get<Is>(t)), 0)...}; }
template<class Ch, class Tr, class... Args> 
auto operator<<(basic_ostream<Ch, Tr>& os, tuple<Args...> const& t) -> basic_ostream<Ch, Tr>& { os << "("; print_tuple(os, t, gen_seq<sizeof...(Args)>()); return os << ")"; }
ostream &operator<<(ostream &o, const vvll &v) { rep(i, v.size()) { rep(j, v[i].size()) o << v[i][j] << " "; o << endl; } return o; }
template <typename T> ostream &operator<<(ostream &o, const vector<T> &v) { o << '['; rep(i, v.size()) o << v[i] << (i != v.size()-1 ? ", " : ""); o << "]";  return o; }
template <typename T> ostream &operator<<(ostream &o, const deque<T> &v) { o << '['; rep(i, v.size()) o << v[i] << (i != v.size()-1 ? ", " : ""); o << "]";  return o; }
template <typename T>  ostream &operator<<(ostream &o, const set<T> &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it << (next(it) != m.end() ? ", " : ""); o << "]";  return o; }
template <typename T>  ostream &operator<<(ostream &o, const unordered_set<T> &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it << (next(it) != m.end() ? ", " : ""); o << "]";  return o; }
template <typename T, typename U>  ostream &operator<<(ostream &o, const map<T, U> &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it << (next(it) != m.end() ? ", " : ""); o << "]";  return o; }
template <typename T, typename U, typename V>  ostream &operator<<(ostream &o, const unordered_map<T, U, V> &m) { o << '['; for (auto it = m.begin(); it != m.end(); it++) o << *it; o << "]";  return o; }
vector<int> range(const int x, const int y) { vector<int> v(y - x + 1); iota(v.begin(), v.end(), x); return v; }
template <typename T> istream& operator>>(istream& i, vector<T>& o) { rep(j, o.size()) i >> o[j]; return i;}
template <typename T, typename S, typename U> ostream &operator<<(ostream &o, const priority_queue<T, S, U> &v) { auto tmp = v; while (tmp.size()) { auto x = tmp.top(); tmp.pop(); o << x << " ";} return o; }
template <typename T> ostream &operator<<(ostream &o, const queue<T> &v) { auto tmp = v; while (tmp.size()) { auto x = tmp.front(); tmp.pop(); o << x << " ";} return o; }
template <typename T> ostream &operator<<(ostream &o, const stack<T> &v) { auto tmp = v; while (tmp.size()) { auto x = tmp.top(); tmp.pop(); o << x << " ";} return o; }
template <typename T> unordered_map<T, ll> counter(vector<T> vec){unordered_map<T, ll> ret; for (auto&& x : vec) ret[x]++; return ret;};
string substr(string s, P x) {return s.substr(x.fi, x.se - x.fi); }
void vizGraph(vvll& g, int mode = 0, string filename = "out.png") { ofstream ofs("./out.dot"); ofs << "digraph graph_name {" << endl; set<P> memo; rep(i, g.size())  rep(j, g[i].size()) { if (mode && (memo.count(P(i, g[i][j])) || memo.count(P(g[i][j], i)))) continue; memo.insert(P(i, g[i][j])); ofs << "    " << i << " -> " << g[i][j] << (mode ? " [arrowhead = none]" : "")<< endl;  } ofs << "}" << endl; ofs.close(); system(((string)"dot -T png out.dot >" + filename).c_str()); }
size_t random_seed; namespace std { using argument_type = P; template<> struct hash<argument_type> { size_t operator()(argument_type const& x) const { size_t seed = random_seed; seed ^= hash<ll>{}(x.fi); seed ^= (hash<ll>{}(x.se) << 1); return seed; } }; }; // hash for various class
struct timeval start; double sec() { struct timeval tv; gettimeofday(&tv, NULL); return (tv.tv_sec - start.tv_sec) + (tv.tv_usec - start.tv_usec) * 1e-6; }
struct init_{init_(){ ios::sync_with_stdio(false); cin.tie(0); gettimeofday(&start, NULL); struct timeval myTime; struct tm *time_st; gettimeofday(&myTime, NULL); time_st = localtime(&myTime.tv_sec); srand(myTime.tv_usec); random_seed = RAND_MAX / 2 + rand() / 2; }} init__;
#define ldout fixed << setprecision(40) 

#define EPS (double)1e-14
#define INF (ll)1e18
#define mo  (ll)(1e9+7)

ll n; vll b;
ll baa[2][2][2] = { {{0,-1},{0,1}}, {{1,3},{1,0}}, };

// i(2<=i<n)よりあとを埋める方法であって、
// 直前に埋めたものがp, 直前の直前に埋めたものがppであり、
// 数列の初めがa0, 最後がcであるようなものの数え上げ
ll dp[2020][2][2] = {};
ll dfs(ll i, ll p, ll pp, ll a0, ll c) {
    if (dp[i][p][pp] >= 0) return dp[i][p][pp];
    if (i == n-1) {
        ll dis;
        dis = baa[b[i-1]][pp][p];
        if (dis != 3 && dis != c) return dp[i][p][pp] = 0;
        dis = baa[b[i]][p][c];
        if (dis != 3 && dis != a0) return dp[i][p][pp] = 0;
        return dp[i][p][pp] = 1;
    } else {
        ll state = baa[b[i-1]][pp][p];
        ll ret = 0; 
        if (state == 0 || state == 3)
            (ret += dfs(i+1, 0, p, a0, c)) %= mo;
        if (state == 1 || state == 3)
            (ret += dfs(i+1, 1, p, a0, c)) %= mo;
        return (dp[i][p][pp] = ret) %= mo;
    }
}

int main(void) {
    cin >> n; assert(4<=n&&n<=2000);
    b.resize(n); cin >> b; rep(i, n) assert(b[i] == 0 || b[i] == 1);

    ll ret = 0;
    vll rule = {0,1,1,1,0,1,1,0};
    rep(maski, 8) if (b[0] == rule[maski]) {
        bitset<3> mask(maski);
        rep(i, 2020) rep(j, 2) rep(h, 2) dp[i][j][h] = -1;
        (ret += dfs(2, mask[0], mask[1], mask[1], mask[2]));
    }
        
    cout << ret % mo << endl;

    return 0;
}
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