結果
問題 |
No.3202 Periodic Alternating Subsequence
|
ユーザー |
|
提出日時 | 2025-07-11 23:00:40 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 495 ms / 2,000 ms |
コード長 | 4,132 bytes |
コンパイル時間 | 2,318 ms |
コンパイル使用メモリ | 208,064 KB |
実行使用メモリ | 7,848 KB |
最終ジャッジ日時 | 2025-07-11 23:00:53 |
合計ジャッジ時間 | 12,804 ms |
ジャッジサーバーID (参考情報) |
judge1 / judge4 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 2 |
other | AC * 24 |
ソースコード
#include <bits/stdc++.h> using namespace std; //入力が必ず-mod<a<modの時. template<const int mod> struct modint{ //mod変更が不可能. public: long long v = 0; static void setmod(int m){} //飾り. static constexpr long long getmod(){return mod;} modint(){v = 0;} modint(int a){v = a<0?a+mod:a;} modint(long long a){v = a<0?a+mod:a;} modint(unsigned int a){v = a;} modint(unsigned long long a){v = a;} long long val()const{return v;} modint &operator=(const modint &b) = default; modint operator+()const{return (*this);} modint operator-()const{return modint(0)-(*this);} modint operator+(const modint b)const{return modint(v)+=b;} modint operator-(const modint b)const{return modint(v)-=b;} modint operator*(const modint b)const{return modint(v)*=b;} modint operator/(const modint b)const{return modint(v)/=b;} modint operator+=(const modint b){ v += b.v; if(v >= mod) v -= mod; return *this; } modint operator-=(const modint b){ v -= b.v; if(v < 0) v += mod; return *this; } modint operator*=(const modint b){v = v*b.v%mod; return *this;} modint operator/=(modint b){ //b!=0 mod素数が必須. if(b == 0) assert(false); int left = mod-2; while(left){if(left&1) *this *= b; b *= b; left >>= 1;} return *this; } modint operator++(){*this += 1; return *this;} modint operator--(){*this -= 1; return *this;} modint operator++(int){*this += 1; return *this;} modint operator--(int){*this -= 1; return *this;} bool operator==(const modint b)const{return v == b.v;} bool operator!=(const modint b)const{return v != b.v;} bool operator>(const modint b)const{return v > b.v;} bool operator>=(const modint b)const{return v >= b.v;} bool operator<(const modint b)const{return v < b.v;} bool operator<=(const modint b)const{return v <= b.v;} modint pow(long long n)const{ modint ret = 1,p = v; if(n < 0) p = p.inv(),n = -n; while(n){ if(n&1) ret *= p; p *= p; n >>= 1; } return ret; } modint inv()const{return modint(1)/v;} //素数mod必須. }; using mint = modint<1000000007>; template<typename T> vector<vector<T>> multima(vector<vector<T>> &A,vector<vector<T>> &B){ assert(A.at(0).size() == B.size() && B.size()); int H = A.size(),W = B.at(0).size(); vector<vector<T>> ret(H,vector<T>(W)); for(int i=0; i<H; i++) for(int k=0; k<W; k++){ for(int l=0; l<A.at(i).size(); l++){ ret.at(i).at(k) += A.at(i).at(l)*B.at(l).at(k); } } return ret; //計算できる行列のみ. } template<typename T> vector<vector<T>> Powmat(vector<vector<T>> A,vector<vector<T>> B,long long N){ //return A^N*B ABは行列; //n*n行列A n*1行列Bと想定 O(n^3*logN). assert(A.size() && A.size() == A.at(0).size() && N >= 0); while(N){ if(N&1) B = multima(A,B); A = multima(A,A); N >>= 1; } return B; } int main(){ ios_base::sync_with_stdio(false); cin.tie(nullptr); string s; cin >> s; long long K; cin >> K; int N = s.size(); vector<vector<mint>> zero = { {1,0,0,0,0,0,0}, {1,1,1,0,0,0,0}, {0,0,1,0,0,0,0}, {2,0,2,1,1,0,0}, {0,0,0,0,1,0,0}, {1,0,1,0,1,1,1}, {0,0,0,0,0,0,1} }, one = { {1,0,0,0,0,0,0}, {0,1,0,0,0,0,0}, {1,1,1,0,0,0,0}, {0,0,0,1,0,0,0}, {2,2,0,1,1,0,0}, {0,0,0,0,0,1,0}, {1,1,0,1,0,1,1} },all = { {1,0,0,0,0,0,0}, {0,1,0,0,0,0,0}, {0,0,1,0,0,0,0}, {0,0,0,1,0,0,0}, {0,0,0,0,1,0,0}, {0,0,0,0,0,1,0}, {0,0,0,0,0,0,1} }; for(auto c : s){ if(c == '0') all = multima(zero,all); else all = multima(one,all); } vector<vector<mint>> dp(7,vector<mint>(1)); dp.at(0).at(0) = 1; dp = Powmat(all,dp,K); // for(int i=0; i<7; i++) cout << dp.at(i).at(0).v << " "; cout << endl; cout << (dp.at(6).at(0)+dp.at(5).at(0)).v << endl; }