結果

問題 No.3202 Periodic Alternating Subsequence
ユーザー hint908
提出日時 2025-07-11 22:40:18
言語 C++23
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 604 ms / 2,000 ms
コード長 5,440 bytes
コンパイル時間 3,972 ms
コンパイル使用メモリ 297,484 KB
実行使用メモリ 7,844 KB
最終ジャッジ日時 2025-07-11 22:40:35
合計ジャッジ時間 16,819 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge3
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 * 2
other AC * 24
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 # 

// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")


#include<bits/stdc++.h>
using namespace std;
using uint = unsigned int;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
template<class T> using V = vector<T>;
template<class T> using VV = V<V<T>>;
template<class T> using VVV = V<VV<T>>;
template<class T> using VVVV = VV<VV<T>>;
#define rep(i,n) for(ll i=0ll;(i)<(n);(i)++)
#define REP(i,a,n) for(ll i=(a);(i)<(n);(i)++)
#define rrep(i,n) for(ll i=(n)-1;(i)>=(0ll);(i)--)
#define RREP(i,a,n) for(ll i=(n)-1;(i)>=(a);(i)--)
const long long INF = (1LL << 60);
const long long mod99 = 998244353;
const long long mod107 = 1000000007;
const long long mod = mod99;
#define eb emplace_back
#define be(v) (v).begin(),(v).end()
#define all(v) (v).begin(),(v).end()
#define foa(i,v) for(auto& (i) : (v))
#define UQ(v) sort(be(v)), (v).erase(unique(be(v)), (v).end())
#define UQ2(v,cmp) sort(be(v)), (v).erase(unique(be(v),cmp), (v).end())
#define UQ3(v,cmp) sort(be(v),cmp), (v).erase(unique(be(v)), (v).end())
#define UQ4(v,cmp,cmp2) sort(be(v), cmp), (v).erase(unique(be(v),cmp2), (v).end())
#define LB(x,v) (lower_bound(be(v),(x))-(v).begin())
#define LB2(x,v,cmp) (lower_bound(be(v),(x),(cmp))-(v).begin())
#define UB(x,v) (upper_bound(be(v),(x))-(v).begin())
#define UB2(x,v,cmp) (upper_bound(be(v),(x),(cmp))-(v).begin())
#define dout()  cout << fixed << setprecision(20)
#define randinit() srand((unsigned)time(NULL))

template<class T, class U> bool chmin(T& t, const U& u) { if (t > u){ t = u; return 1;} return 0; }
template<class T, class U> bool chmax(T& t, const U& u) { if (t < u){ t = u; return 1;} return 0; }


ll Rnd(ll L=0, ll R=mod99){return rand()%(R-L)+L;}


VV<ll> matmul(VV<ll> v, VV<ll> w, ll p=(1ll<<60)){
    ll n1 = v.size();
    ll n2 = w.size();
    ll n3 = w[0].size();
    VV<ll> ret(n1, V<ll>(n3, 0));
    rep(i, n1) rep(j,n2) rep(k,n3) (ret[i][k] += v[i][j]*w[j][k]) %= p;
    return ret;
}

VV<ll> matpow(VV<ll> v, ll k, ll p){
    if(k == 1) return v;
    ll n = v.size();
    VV<ll> ret(n, V<ll>(n, 0));
    rep(i, n) ret[i][i] = 1;
    if(k == 0) return ret;
    
    VV<ll> w = matpow(v, k/2, p);
    w = matmul(w, w, p);
    if(k%2) w = matmul(w, v, p);
    
    return w;
    
}


struct Combination{
    vector<long long> fac, inv, finv;
    long long MOD;
    Combination(long long N = 200100, long long p = 998244353) : fac(N, 1), inv(N, 1), finv(N, 1), MOD(p){
        for(long long i = 2; i < N; i++){
            fac[i] = fac[i-1] * i % MOD;
            inv[i] = MOD - inv[MOD%i] * (MOD/i) % MOD;
            finv[i] = finv[i-1] * inv[i] % MOD;
        }
    }
    long long com(long long n, long long k){
        if(n < k) return 0;
        if(n < 0 || k < 0) return 0;
        return fac[n] * finv[k] % MOD * finv[n-k] % MOD;
    }
    
    long long per(long long n, long long k){
        if(n < k) return 0;
        if(n < 0 || k < 0) return 0;
        return fac[n] * finv[n-k] % MOD;
    }
};

long long modpow(long long n, long long k, long long p = mod){
    long long a = n % p;
    long long ans = 1;
    while(k != 0) {
        if(k & 1) ans = ans * a % p;
        k /= 2;
        a = a * a % p;
    }
    
    return ans;  
}

// n^(-1) ≡ b (mod p) となる b を求める
long long modinv(long long n, long long p = mod) { 
//    if(n == 1) return 1;
//    return p - modinv(p % n) * (p / n) % p;
    return modpow(n, p - 2, p);
}

// n^k ≡ b (mod p) となる最小の k を求める
long long modlog(long long n, long long b, long long p = mod){
  
    long long sqrt_p = sqrt(p);
    unordered_map<long long , long long> n_pow;
    long long memo = 1;
    
    for(long long i = 0; i < sqrt_p; i ++){
        if(!n_pow.count(memo)) n_pow[memo] = i;
        memo = memo * n % p; 
    }
    
    memo = modinv(memo, p);
    long long ans = 0;
    while(!n_pow.count(b)){
        if(ans >= p) return -1;
        ans += sqrt_p;
        b = b * memo % p;
    }
  
    ans += n_pow[b];
    return ans % (p - 1);

}

// ax + by = gcd(a, b) を満たす (x, y) が格納される
long long ext_gcd(long long a, long long b, long long &x, long long &y){
    if(b == 0){
        x = 1;
        y = 0;
        return a;
    }
    long long d = ext_gcd(b, a%b, y, x);
    y -= a/b*x;
    return d;
}

void solve(){
    VV<ll> v(6, V<ll>(6, 0));
    v[0][0] = 1;
    v[1][1] = 1;
    v[2][2] = 1;
    v[3][3] = 1;
    v[4][4] = 1;
    v[5][5] = 1;
    VV<ll> w = v;
    
    VV<ll> a = v;
    v[0][3] ++;
    v[1][4] ++;
    v[1][3] ++;
    v[2][3] ++;
    v[2][4] += 2;
    v[2][5] ++;
    
    w[3][0] ++;
    w[4][1] ++;
    w[4][0] ++;
    w[5][0] ++;
    w[5][1] += 2;
    w[5][2] ++;
    
    
    string s;
    ll k;
    cin >> s >> k;
    for(auto c:s){
        if(c == '0') a = matmul(a, v, mod107);
        else a = matmul(a, w, mod107);
        
        // rep(i, 6) rep(j, 6) cout << a[i][j] << " \n"[j==5];
        // cout << endl;
    }
    auto vv = matpow(a, k, mod107);
    // rep(i, 6) rep(j, 6) cout << vv[i][j] << " \n"[j==5];
    
    VV<ll> ww = {{1},{0},{0}, {1},{0},{0}}; 
    auto vw = matmul(vv, ww, mod107);
    // for(auto x:vw){
    //     for(auto xx:x) cout << xx << " ";
    //     cout << endl;
    // }
    cout << (vw[2][0]+vw[5][0])%mod107 << endl;
    
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int t=1;
    // cin >> t;
    rep(i,t) solve();
}
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