結果
問題 | No.269 見栄っ張りの募金活動 |
ユーザー |
|
提出日時 | 2021-02-15 19:20:53 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 5 ms / 5,000 ms |
コード長 | 2,284 bytes |
コンパイル時間 | 2,509 ms |
コンパイル使用メモリ | 193,836 KB |
最終ジャッジ日時 | 2025-01-18 21:13:02 |
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 * 3 |
other | AC * 22 |
ソースコード
#include <bits/stdc++.h>using namespace std;#define rep(i,n) for (int i = 0; i < (n); ++i)using ll = long long;using pii = pair<int,int>;template< int mod >struct ModInt {int x;ModInt() : x(0) {}ModInt(int64_t y) : x(y >= 0 ? y % mod : (mod - (-y) % mod) % mod) {}ModInt &operator+=(const ModInt &p) {if((x += p.x) >= mod) x -= mod;return *this;}ModInt &operator-=(const ModInt &p) {if((x += mod - p.x) >= mod) x -= mod;return *this;}ModInt &operator*=(const ModInt &p) {x = (int) (1LL * x * p.x % mod);return *this;}ModInt &operator/=(const ModInt &p) {*this *= p.inverse();return *this;}ModInt operator-() const { return ModInt(-x); }ModInt operator+(const ModInt &p) const { return ModInt(*this) += p; }ModInt operator-(const ModInt &p) const { return ModInt(*this) -= p; }ModInt operator*(const ModInt &p) const { return ModInt(*this) *= p; }ModInt operator/(const ModInt &p) const { return ModInt(*this) /= p; }bool operator==(const ModInt &p) const { return x == p.x; }bool operator!=(const ModInt &p) const { return x != p.x; }ModInt inverse() const {int a = x, b = mod, u = 1, v = 0, t;while(b > 0) {t = a / b;swap(a -= t * b, b);swap(u -= t * v, v);}return ModInt(u);}ModInt pow(int64_t n) const {ModInt ret(1), mul(x);while(n > 0) {if(n & 1) ret *= mul;mul *= mul;n >>= 1;}return ret;}friend ostream &operator<<(ostream &os, const ModInt &p) {return os << p.x;}friend istream &operator>>(istream &is, ModInt &a) {int64_t t;is >> t;a = ModInt< mod >(t);return (is);}static int get_mod() { return mod; }};constexpr int MOD = 1e9 + 7;using mint = ModInt< MOD >;int main(){int N, S, K; cin >> N >> S >> K;/*a0 + (a0+K + a1) + (a0+K+a1+K + a2) + ...= (N-1)N/2 * K + Na0 + (N-1)a1 + ..//*/S -= (N-1)*N/2 * K;if(S < 0){cout << 0 << endl;return 0;}vector dp(S+1, mint(1));/*dp_i+1,j = dp_i,j + dp_i,j-(n-i+1) + dp_i,j-2(n-i+1) + ...= dp_i,j + dp_i+1,j-(n-i)//*/rep(i,N-1){for(int j = N-i; j <= S; j++){dp[j] += dp[j-(N-i)];}}cout << dp[S] << endl;}