結果
問題 | No.1518 Simple Combinatorics |
ユーザー |
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提出日時 | 2021-05-28 20:28:17 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 3 ms / 2,000 ms |
コード長 | 5,224 bytes |
コンパイル時間 | 1,461 ms |
コンパイル使用メモリ | 133,792 KB |
最終ジャッジ日時 | 2025-01-21 19:05:03 |
ジャッジサーバーID (参考情報) |
judge5 / judge3 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 19 |
ソースコード
#include <iostream>#include <cstdio>#include <cstdlib>#include <algorithm>#include <cmath>#include <vector>#include <set>#include <map>#include <unordered_set>#include <unordered_map>#include <queue>#include <ctime>#include <cassert>#include <complex>#include <string>#include <cstring>#include <chrono>#include <random>#include <bitset>#include <fstream>using namespace std;#define int long long#define ii pair <int, int>#define app push_back#define all(a) a.begin(), a.end()#define bp __builtin_popcountll#define ll long long#define mp make_pair#define x first#define y second#define Time (double)clock()/CLOCKS_PER_SEC#define debug(x) std::cerr << #x << ": " << x << '\n';#define FORI(i,a,b) for (int i = (a); i < (b); ++i)#define FOR(i,a) FORI(i,0,a)#define ROFI(i,a,b) for (int i = (b)-1; i >= (a); --i)#define ROF(i,a) ROFI(i,0,a)#define rep(a) FOR(_,a)#define each(a,x) for (auto& a: x)#define FORN(i, n) FORI(i, 1, n + 1)using vi = vector<int>;template <typename T>std::istream& operator >>(std::istream& input, std::pair <T, T> & data){input >> data.x >> data.y;return input;}template <typename T>std::istream& operator >>(std::istream& input, std::vector<T>& data){for (T& x : data)input >> x;return input;}template <typename T>std::ostream& operator <<(std::ostream& output, const pair <T, T> & data){output << "(" << data.x << "," << data.y << ")";return output;}template <typename T>std::ostream& operator <<(std::ostream& output, const std::vector<T>& data){for (const T& x : data)output << x << " ";return output;}ll div_up(ll a, ll b) { return a/b+((a^b)>0&&a%b); } // divide a by b rounded upll div_down(ll a, ll b) { return a/b-((a^b)<0&&a%b); } // divide a by b rounded downll math_mod(ll a, ll b) { return a - b * div_down(a, b); }#define tcT template<class T#define tcTU tcT, class UtcT> using V = vector<T>;tcT> bool ckmin(T& a, const T& b) {return b < a ? a = b, 1 : 0;} // set a = min(a,b)tcT> bool ckmax(T& a, const T& b) {return a < b ? a = b, 1 : 0;}ll gcd(ll a, ll b) {while (b) {tie(a, b) = mp(b, a % b);}return a;}int Bit(int mask, int bit) { return (mask >> bit) & 1; }template<int MOD, int RT> struct mint {static const int mod = MOD;static constexpr mint rt() { return RT; } // primitive root for FFTint v; explicit operator int() const { return v; } // explicit -> don't silently convert to intmint() { v = 0; }mint(ll _v) { v = (int)((-MOD < _v && _v < MOD) ? _v : _v % MOD);if (v < 0) v += MOD; }friend bool operator==(const mint& a, const mint& b) {return a.v == b.v; }friend bool operator!=(const mint& a, const mint& b) {return !(a == b); }friend bool operator<(const mint& a, const mint& b) {return a.v < b.v; }friend string ts(mint a) { return to_string(a.v); }mint& operator+=(const mint& m) {if ((v += m.v) >= MOD) v -= MOD;return *this; }mint& operator-=(const mint& m) {if ((v -= m.v) < 0) v += MOD;return *this; }mint& operator*=(const mint& m) {v = (int)((ll)v*m.v%MOD); return *this; }mint& operator/=(const mint& m) { return (*this) *= inv(m); }friend mint pow(mint a, ll p) {mint ans = 1; assert(p >= 0);for (; p; p /= 2, a *= a) if (p&1) ans *= a;return ans; }mint & operator ^=(const int &p) { return (*this) = pow(this, p); }friend mint inv(const mint& a) { assert(a.v != 0);return pow(a,MOD-2); }mint operator-() const { return mint(-v); }mint& operator++() { return *this += 1; }mint& operator--() { return *this -= 1; }friend mint operator+(mint a, const mint& b) { return a += b; }friend mint operator-(mint a, const mint& b) { return a -= b; }friend mint operator*(mint a, const mint& b) { return a *= b; }friend mint operator/(mint a, const mint& b) { return a /= b; }friend mint operator^(mint a, const int p) { return pow(a, p); }};const int MOD = 1e9+7;typedef mint<MOD,5> mi; // 5 is primitive root for both common modstypedef vector<mi> vmi;std::ostream& operator << (std::ostream& o, const mi& a){cout << a.v;return o;}vector<vmi> scmb; // small combinationsvoid genComb(int SZ) {scmb.assign(SZ,vmi(SZ)); scmb[0][0] = 1;FORI(i,1,SZ) FOR(j,i+1)scmb[i][j] = scmb[i-1][j]+(j?scmb[i-1][j-1]:0);}vmi invs, fac, ifac; // make sure to convert to LL before doing any multiplications ...void genFac(int SZ) {invs.resize(SZ), fac.resize(SZ), ifac.resize(SZ);invs[1] = fac[0] = ifac[0] = 1;FORI(i,2,SZ) invs[i] = mi(-(ll)MOD/i*(int)invs[MOD%i]);FORI(i,1,SZ) {fac[i] = fac[i-1]*i;ifac[i] = ifac[i-1]*invs[i];}}mi comb(int a, int b) {if (a < b || b < 0) return 0;assert(a < fac.size());return fac[a]*ifac[b]*ifac[a-b];}signed main() {#ifdef LOCAL#else#define endl '\n'ios_base::sync_with_stdio(0); cin.tie(0);#endifint n, k;cin >> n >> k;cout << n * (1 - ((mi(n-1)/n)^k)) * (mi(n)^k) << endl;}