結果
問題 |
No.269 見栄っ張りの募金活動
|
ユーザー |
![]() |
提出日時 | 2019-11-19 16:07:34 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 59 ms / 5,000 ms |
コード長 | 4,538 bytes |
コンパイル時間 | 1,360 ms |
コンパイル使用メモリ | 121,728 KB |
最終ジャッジ日時 | 2025-01-08 04:08:11 |
ジャッジサーバーID (参考情報) |
judge3 / judge1 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 22 |
ソースコード
#include <algorithm> #include <bitset> #include <cassert> #include <cctype> #include <chrono> #define _USE_MATH_DEFINES #include <cmath> #include <cstring> #include <ctime> #include <deque> #include <functional> #include <iostream> #include <iomanip> #include <iterator> #include <map> #include <numeric> #include <queue> #include <set> #include <sstream> #include <stack> #include <string> #include <tuple> #include <utility> #include <vector> using namespace std; #define FOR(i,m,n) for(int i=(m);i<(n);++i) #define REP(i,n) FOR(i,0,n) #define ALL(v) (v).begin(),(v).end() const int INF = 0x3f3f3f3f; const long long LINF = 0x3f3f3f3f3f3f3f3fLL; const double EPS = 1e-8; const int MOD = 1000000007; // const int MOD = 998244353; const int dy[] = {1, 0, -1, 0}, dx[] = {0, -1, 0, 1}; // const int dy[] = {1, 1, 0, -1, -1, -1, 0, 1}, // dx[] = {0, -1, -1, -1, 0, 1, 1, 1}; struct IOSetup { IOSetup() { cin.tie(nullptr); ios_base::sync_with_stdio(false); cout << fixed << setprecision(20); cerr << fixed << setprecision(10); } } iosetup; /*-------------------------------------------------*/ int mod = MOD; struct ModInt { unsigned val; ModInt(): val(0) {} ModInt(long long x) : val(x >= 0 ? x % mod : x % mod + mod) {} ModInt pow(long long exponent) { ModInt tmp = *this, res = 1; while (exponent > 0) { if (exponent & 1) res *= tmp; tmp *= tmp; exponent >>= 1; } return res; } ModInt &operator+=(const ModInt &rhs) { if((val += rhs.val) >= mod) val -= mod; return *this; } ModInt &operator-=(const ModInt &rhs) { if((val += mod - rhs.val) >= mod) val -= mod; return *this; } ModInt &operator*=(const ModInt &rhs) { val = static_cast<unsigned long long>(val) * rhs.val % mod; return *this; } ModInt &operator/=(const ModInt &rhs) { return *this *= rhs.inv(); } bool operator==(const ModInt &rhs) const { return val == rhs.val; } bool operator!=(const ModInt &rhs) const { return val != rhs.val; } bool operator<(const ModInt &rhs) const { return val < rhs.val; } bool operator<=(const ModInt &rhs) const { return val <= rhs.val; } bool operator>(const ModInt &rhs) const { return val > rhs.val; } bool operator>=(const ModInt &rhs) const { return val >= rhs.val; } ModInt operator-() const { return ModInt(val ? mod - val : 0); } ModInt operator+(const ModInt &rhs) const { return ModInt(*this) += rhs; } ModInt operator-(const ModInt &rhs) const { return ModInt(*this) -= rhs; } ModInt operator*(const ModInt &rhs) const { return ModInt(*this) *= rhs; } ModInt operator/(const ModInt &rhs) const { return ModInt(*this) /= rhs; } friend ostream &operator<<(ostream &os, const ModInt &rhs) { return os << rhs.val; } friend istream &operator>>(istream &is, ModInt &rhs) { long long x; is >> x; rhs = ModInt(x); return is; } private: ModInt inv() const { // if (__gcd(val, mod) != 1) assert(false); unsigned a = val, b = mod; int x = 1, y = 0; while (b) { unsigned tmp = a / b; swap(a -= tmp * b, b); swap(x -= tmp * y, y); } return ModInt(x); } }; int abs(const ModInt &x) { return x.val; } struct Combinatorics { int val; vector<ModInt> fact, fact_inv, inv; Combinatorics(int val = 10000000) : val(val), fact(val + 1), fact_inv(val + 1), inv(val + 1) { fact[0] = 1; FOR(i, 1, val + 1) fact[i] = fact[i - 1] * i; fact_inv[val] = ModInt(1) / fact[val]; for (int i = val; i > 0; --i) fact_inv[i - 1] = fact_inv[i] * i; FOR(i, 1, val + 1) inv[i] = fact[i - 1] * fact_inv[i]; } ModInt nCk(int n, int k) { if (n < 0 || n < k || k < 0) return ModInt(0); // assert(n <= val && k <= val); return fact[n] * fact_inv[k] * fact_inv[n - k]; } ModInt nPk(int n, int k) { if (n < 0 || n < k || k < 0) return ModInt(0); // assert(n <= val); return fact[n] * fact_inv[n - k]; } ModInt nHk(int n, int k) { if (n < 0 || k < 0) return ModInt(0); return (k == 0 ? ModInt(1) : nCk(n + k - 1, k)); } }; template <typename T> vector<vector<T> > pf_init(int group, int sum) { vector<vector<T> > pf(group + 1, vector<T>(sum + 1, 0)); pf[0][0] = 1; FOR(i, 1, group + 1) REP(j, sum + 1) { if (j - i >= 0) { pf[i][j] = pf[i][j - i] + pf[i - 1][j]; } else { pf[i][j] = pf[i - 1][j]; } } return pf; } int main() { int n, s, k; cin >> n >> s >> k; FOR(i, 1, n) s -= k * i; if (s < 0) { cout << 0 << '\n'; return 0; } auto pf = pf_init<ModInt>(n, s); cout << pf[n][s] << '\n'; return 0; }