結果

問題 No.916 Encounter On A Tree
ユーザー hitonanodehitonanode
提出日時 2019-10-25 22:16:03
言語 C++14
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 234 ms / 2,000 ms
コード長 4,945 bytes
コンパイル時間 1,698 ms
コンパイル使用メモリ 172,916 KB
実行使用メモリ 101,700 KB
最終ジャッジ日時 2024-09-13 04:13:48
合計ジャッジ時間 16,906 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge4
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 * 5
other AC * 56
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 # 

#include <bits/stdc++.h>
using namespace std;
using lint = long long int;
using pint = pair<int, int>;
using plint = pair<lint, lint>;
struct fast_ios { fast_ios(){ cin.tie(0); ios::sync_with_stdio(false); cout << fixed << setprecision(20); }; } fast_ios_;
#define ALL(x) (x).begin(), (x).end()
#define SZ(x) ((lint)(x).size())
#define POW2(n) (1LL << (n))
#define FOR(i, begin, end) for(int i=(begin),i##_end_=(end);i<i##_end_;i++)
#define IFOR(i, begin, end) for(int i=(end)-1,i##_begin_=(begin);i>=i##_begin_;i--)
#define REP(i, n) FOR(i,0,n)
#define IREP(i, n) IFOR(i,0,n)
template<typename T> void ndarray(vector<T> &vec, int len) { vec.resize(len); }
template<typename T, typename... Args> void ndarray(vector<T> &vec, int len, Args... args) { vec.resize(len); for (auto &v : vec) ndarray(v, args...); }
template<typename T> bool mmax(T &m, const T q) { if (m < q) {m = q; return true;} else return false; }
template<typename T> bool mmin(T &m, const T q) { if (m > q) {m = q; return true;} else return false; }
template<typename T1, typename T2> pair<T1, T2> operator+(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first + r.first, l.second + r.second); }
template<typename T1, typename T2> pair<T1, T2> operator-(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first - r.first, l.second - r.second); }
template<typename T> istream &operator>>(istream &is, vector<T> &vec){ for (auto &v : vec) is >> v; return is; }
///// This part below is only for debug, not used /////
template<typename T> ostream &operator<<(ostream &os, const vector<T> &vec){ os << "["; for (auto v : vec) os << v << ","; os << "]"; return os; }
template<typename T> ostream &operator<<(ostream &os, const deque<T> &vec){ os << "deq["; for (auto v : vec) os << v << ","; os << "]"; return os; }
template<typename T> ostream &operator<<(ostream &os, const set<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream &operator<<(ostream &os, const unordered_set<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream &operator<<(ostream &os, const multiset<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T> ostream &operator<<(ostream &os, const unordered_multiset<T> &vec){ os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template<typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &pa){ os << "(" << pa.first << "," << pa.second << ")"; return os; }
template<typename TK, typename TV> ostream &operator<<(ostream &os, const map<TK, TV> &mp){ os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; }
template<typename TK, typename TV> ostream &operator<<(ostream &os, const unordered_map<TK, TV> &mp){ os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; }
#define dbg(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ") " << __FILE__ << endl;
///// END /////
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/tag_and_trait.hpp>
using namespace __gnu_pbds; // find_by_order(), order_of_key()
template<typename TK> using pbds_set = tree<TK, null_type, less<TK>, rb_tree_tag, tree_order_statistics_node_update>;
template<typename TK, typename TV> using pbds_map = tree<TK, TV, less<TK>, rb_tree_tag, tree_order_statistics_node_update>;
*/

constexpr lint MOD = 1000000007;
vector<lint> fac, facInv, inv;
// Solve ax+by=gcd(a, b)
lint extgcd(lint a, lint b, lint &x, lint &y)
{
    lint d = a;
    if (b != 0) d = extgcd(b, a % b, y, x), y -= (a / b) * x;
    else x = 1, y = 0;
    return d;
}
// Calc a^(-1) (MOD m)
lint mod_inverse(lint a, lint m=MOD)
{
    if (a == 0) exit(8);
    lint x, y;
    extgcd(a, m, x, y);
    return (m + x % m) % m;
}
void facInit(int nmax)
{
    fac = facInv = inv = vector<lint>(nmax + 1, 1);
    for (int i = 2; i <= nmax; i++)
    {
        fac[i] = fac[i-1] * i % MOD;
        inv[i] = MOD - inv[MOD%i] * (MOD/i) % MOD;
        facInv[i] = facInv[i-1] * inv[i] % MOD;
    }
}

int dd(int x)
{
    return 32 - __builtin_clz(x);
}
void ZERO()
{
    puts("0");
    exit(0);
}

int main()
{
    facInit(1 << 22);
    int D, L, R, K;
    cin >> D >> L >> R >> K;
    int dl = dd(L), dr = dd(R);
    int k = K - (dr - dl);
    if (k % 2 or k < 0)
    {
        ZERO();
    }
    k /= 2;
    int r = dl - k;
    if (r <= 0) ZERO();
    dbg(dl);
    dbg(dr);
    dbg(r);

    lint ret = 1;
    REP(i, D) ret = ret * fac[1 << i] % MOD;
    dbg(ret);

    if (dl == r)
    {
        ret = ret * mod_inverse(1 << (r - 1)) % MOD;
    }
    else if (dl == dr)
    {
        ret = ret * mod_inverse((1 << (dr - 1)) - 1) % MOD * ((1 << (dr - r - 1))) % MOD;
    }
    else
    {
        ret = ret * mod_inverse(1 << r) % MOD;
    }
    cout << ret % MOD << endl;
}
0