結果

問題 No.1702 count good string
ユーザー jupiro
提出日時 2021-10-08 22:50:48
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 9 ms / 2,000 ms
コード長 3,363 bytes
コンパイル時間 2,423 ms
コンパイル使用メモリ 201,728 KB
最終ジャッジ日時 2025-01-24 23:04:40
ジャッジサーバーID
(参考情報)
judge2 / judge1
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 3
other AC * 47
権限があれば一括ダウンロードができます

ソースコード

diff #
プレゼンテーションモードにする

#include <bits/stdc++.h>
using ll = long long;
using std::cin;
using std::cout;
using std::endl;
std::mt19937 rnd(std::chrono::steady_clock::now().time_since_epoch().count());
template <class T>
inline bool chmax(T &a, T b)
{
if (a < b)
{
a = b;
return 1;
}
return 0;
}
template <class T>
inline bool chmin(T &a, T b)
{
if (a > b)
{
a = b;
return 1;
}
return 0;
}
const int inf = (int)1e9 + 7;
const long long INF = 1LL << 60;
template <int mod>
struct ModInt
{
int x;
ModInt() : x(0) {}
ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}
ModInt &operator+=(const ModInt &p)
{
if ((x += p.x) >= mod)
x -= mod;
return *this;
}
ModInt &operator-=(const ModInt &p)
{
if ((x += mod - p.x) >= mod)
x -= mod;
return *this;
}
ModInt &operator*=(const ModInt &p)
{
x = (int)(1LL * x * p.x % mod);
return *this;
}
ModInt &operator/=(const ModInt &p)
{
*this *= p.inverse();
return *this;
}
ModInt operator-() const { return ModInt(-x); }
ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }
ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }
ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }
ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }
bool operator==(const ModInt &p) const { return x == p.x; }
bool operator!=(const ModInt &p) const { return x != p.x; }
ModInt inverse() const
{
int a = x, b = mod, u = 1, v = 0, t;
while (b > 0)
{
t = a / b;
std::swap(a -= t * b, b);
std::swap(u -= t * v, v);
}
return ModInt(u);
}
ModInt pow(int64_t n) const
{
ModInt ret(1), mul(x);
while (n > 0)
{
if (n & 1)
ret *= mul;
mul *= mul;
n >>= 1;
}
return ret;
}
friend std::ostream &operator<<(std::ostream &os, const ModInt &p)
{
return os << p.x;
}
friend std::istream &operator>>(std::istream &is, ModInt &a)
{
int64_t t;
is >> t;
a = ModInt<mod>(t);
return (is);
}
static int get_mod() { return mod; }
};
constexpr int mod = (int)1e9 + 7;
using mint = ModInt<mod>;
void solve([[maybe_unused]] int CASE)
{
int n;
std::string s;
cin >> n >> s;
const std::string t = "yukicoder";
std::vector dp(2, std::vector(2, std::vector<mint>(t.size() + 1)));
int cur = 0, nxt = 1;
dp[0][0][0] = 1;
for (int i = 0; i < n; ++i)
{
for (int j = 0; j < 2; ++j)
{
for (int k = 0; k <= (int)t.size(); ++k)
{
dp[nxt][j][k] = 0;
}
}
for (int j = 0; j < 2; ++j)
{
for (int k = 0; k <= (int)t.size(); ++k)
{
dp[nxt][j][k] += dp[cur][j][k];
if (k + 1 <= (int)t.size())
{
if (s[i] == '?' and j == 0)
{
dp[nxt][1][k + 1] += dp[cur][j][k];
}
if (s[i] == t[k])
{
dp[nxt][j][k + 1] += dp[cur][j][k];
}
}
}
}
std::swap(cur, nxt);
}
mint res = 0;
for (int i = 0; i < 2; ++i)
{
res += dp[cur][i][(int)t.size()];
}
cout << res << "\n";
}
int main()
{
std::cin.tie(nullptr);
std::ios::sync_with_stdio(false);
int kkt = 1;
// cin >> kkt;
for (int jupi = 1; jupi <= kkt; jupi++)
solve(jupi);
return 0;
}
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