結果

問題 No.1331 Moving Penguin
ユーザー ForestedForested
提出日時 2021-01-08 21:58:28
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 294 ms / 1,500 ms
コード長 3,981 bytes
コンパイル時間 1,885 ms
コンパイル使用メモリ 198,292 KB
最終ジャッジ日時 2025-01-17 11:55:13
ジャッジサーバーID
（参考情報） 		judge2 / judge2
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ファイルパターン 結果
other AC * 49
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 # 

// Template
#include "bits/stdc++.h"
#define rep_override(x, y, z, name, ...) name
#define rep2(i, n) for (int i = 0; i < (int)(n); ++i)
#define rep3(i, l, r) for (int i = (int)(l); i < (int)(r); ++i)
#define rep(...) rep_override(__VA_ARGS__, rep3, rep2)(__VA_ARGS__)
#define all(x) (x).begin(), (x).end()
using namespace std;
using ll = long long;
constexpr int inf = 1001001001;
constexpr ll infll = 3003003003003003003LL;
template <typename T>
inline bool chmin(T &x, const T &y) {
    if (x > y) {
        x = y;
        return true;
    }
    return false;
}
template <typename T> 
inline bool chmax(T &x, const T &y) {
    if (x < y) {
        x = y;
        return true;
    }
    return false;
}
template <typename T>
istream &operator>>(istream &is, vector<T> &vec) {
    for (T &element : vec) is >> element;
    return is;
}
template <typename T>
ostream &operator<<(ostream &os, const vector<T> &vec) {
    for (int i = 0, vec_len = (int)vec.size(); i < vec_len; ++i) {
        os << vec[i] << (i + 1 == vec_len ? "" : " ");
    }
    return os;
}
struct IOSET {
    IOSET() {
        cin.tie(nullptr);
        ios::sync_with_stdio(false);
        cout << fixed << setprecision(10);
    }
} ioset;

// Mod-Int
#include <iostream>
#include <type_traits>

template <unsigned int mod, std::enable_if_t<mod >= 1u && mod < (1u << 31)> * = nullptr>
struct ModInt {
    unsigned int val;
    
    ModInt() : val(0) {}
    
    ModInt(long long x) : val(x < 0 ? x % mod + mod : (unsigned long long)x % mod) {}
    
    ModInt<mod> &operator+=(const ModInt<mod> &x) {
        val += x.val;
        if (val >= mod) val -= mod;
        return *this;
    }
    
    ModInt<mod> &operator-=(const ModInt<mod> &x) {
        if (val < x.val) val += mod;
        val -= x.val;
        return *this;
    }
    
    ModInt<mod> &operator*=(const ModInt<mod> &x) {
        unsigned long long s = (unsigned long long)val * x.val;
        val = (unsigned int)(s % mod);
        return *this;
    }
    
    ModInt<mod> operator+() const {
        return *this;
    }
    
    ModInt<mod> operator-() const {
        return ModInt<mod>(0u) - *this;
    }
    
    friend ModInt<mod> operator+(const ModInt<mod> &x, const ModInt<mod> &y) {
        return ModInt<mod>(x) += y;
    }
    
    friend ModInt<mod> operator-(const ModInt<mod> &x, const ModInt<mod> &y) {
        return ModInt<mod>(x) -= y;
    }
    
    friend ModInt<mod> operator*(const ModInt<mod> &x, const ModInt<mod> &y) {
        return ModInt<mod>(x) *= y;
    }
    
    friend std::istream &operator>>(std::istream &is, ModInt<mod> &x) {
        is >> x.val;
        // x.value %= mod;
        return is;
    }
    
    friend std::ostream &operator<<(std::ostream &os, const ModInt<mod> &x) {
        os << x.val;
        return os;
    }
    
    ModInt<mod> pow(unsigned long long x) const {
        ModInt<mod> res(1), s(*this);
        while (x) {
            if (x & 1) res *= s;
            s *= s;
            x >>= 1;
        }
        return res;
    }
    
    // --- mod is prime ---
    ModInt<mod> &operator/=(const ModInt<mod> &x) {
        *this *= x.pow(mod - 2);
        return *this;
    }
    
    friend ModInt<mod> operator/(const ModInt<mod> &x, const ModInt<mod> &y) {
        return ModInt<mod>(x) /= y;
    }
};

using Mint = ModInt<1000000007>;

// Main
int main() {
    int n;
    cin >> n;
    vector<int> a(n);
    cin >> a;
    
    const int b = 500;
    
    vector<vector<Mint>> d(b, vector<Mint>(b, Mint(0)));
    vector<Mint> dp(n, Mint(0));
    dp[0] = Mint(1);
    rep(i, n) {
        rep(j, 1, b) {
            dp[i] += d[j][i % j];
        }
        if (i == n - 1) continue;
        if (a[i] != 1) {
            dp[i + 1] += dp[i];
        }
        if (a[i] < b) {
            d[a[i]][i % a[i]] += dp[i];
        } else {
            for (int j = i + a[i]; j < n; j += a[i]) {
                dp[j] += dp[i];
            }
        }
    }
    
    cout << dp[n - 1] << "\n";
}
0