結果
問題 | No.533 Mysterious Stairs |
ユーザー |
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提出日時 | 2020-06-23 12:52:09 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 79 ms / 5,000 ms |
コード長 | 3,040 bytes |
コンパイル時間 | 1,789 ms |
コンパイル使用メモリ | 198,192 KB |
最終ジャッジ日時 | 2025-01-11 09:34:53 |
ジャッジサーバーID (参考情報) |
judge5 / judge1 |
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ファイルパターン | 結果 |
---|---|
other | AC * 28 |
ソースコード
#include <bits/stdc++.h>#define rep(i, a) for (int i = (int)0; i < (int)a; ++i)#define rrep(i, a) for (int i = (int)a - 1; i >= 0; --i)#define REP(i, a, b) for (int i = (int)a; i < (int)b; ++i)#define RREP(i, a, b) for (int i = (int)a - 1; i >= b; --i)#define pb push_back#define eb emplace_back#define all(x) x.begin(), x.end()#define rall(x) x.rbegin(), x.rend()using ll = long long;constexpr ll mod = 1e9 + 7;constexpr ll INF = 1LL << 60;template <class T>inline bool chmin(T &a, T b){if (a > b){a = b;return true;}return false;}template <class T>inline bool chmax(T &a, T b){if (a < b){a = b;return true;}return false;}ll gcd(ll n, ll m){ll tmp;while (m != 0){tmp = n % m;n = m;m = tmp;}return n;}ll lcm(ll n, ll m){return abs(n) / gcd(n, m) * abs(m); //gl=xy}using namespace std;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;swap(a -= t * b, b);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 ostream &operator<<(ostream &os, const ModInt &p) {return os << p.x;}friend istream &operator>>(istream &is, ModInt &a) {int64_t t;is >> t;a = ModInt< mod >(t);return (is);}static int get_mod() { return mod; }};using modint = ModInt< mod >;void solve(){int n;cin>>n;vector<vector<modint>>dp(n+5,vector<modint>(3));dp[0][0]=1;rep(i,n){if(i){rep(j,3){dp[i+(j+1)][j]+=dp[i][(j-1+3)%3];dp[i+(j+1)][j]+=dp[i][(j-2+3)%3];}}else{dp[i+1][0]+=dp[i][0];dp[i+2][1]+=dp[i][0];dp[i+3][2]+=dp[i][0];}}modint ans=dp[n][0]+dp[n][1]+dp[n][2];cout<<ans<<"\n";}int main(){ios::sync_with_stdio(false);cin.tie(0);cout << fixed << setprecision(15);solve();return 0;}