結果
問題 | No.1683 Robot Guidance |
ユーザー |
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提出日時 | 2021-09-17 22:18:12 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 139 ms / 2,000 ms |
コード長 | 4,031 bytes |
コンパイル時間 | 1,153 ms |
コンパイル使用メモリ | 117,476 KB |
最終ジャッジ日時 | 2025-01-24 15:04:56 |
ジャッジサーバーID (参考情報) |
judge1 / judge5 |
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ファイルパターン | 結果 |
---|---|
sample | AC * 3 |
other | AC * 38 |
ソースコード
#include <iostream> #include <algorithm> #include <iomanip> #include <vector> #include <queue> #include <set> #include <map> #include <tuple> #include <cmath> #include <numeric> #include <functional> #include <cassert> #define debug_value(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << #x << "=" << x << endl; #define debug(x) cerr << "line" << __LINE__ << ":<" << __func__ << ">:" << x << endl; template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; } template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; } using namespace std; typedef long long ll; const ll MOD = 1000000007; class ModInt{ public: ll v; ModInt(ll _v = 0){ if(_v < 0) _v = (_v%MOD)+MOD; if(_v >= MOD) _v %= MOD; v = _v; } ModInt operator+(ll n){ return ModInt((v+n)%MOD); } ModInt operator-(ll n){ return ModInt((v-n+MOD)%MOD); } ModInt operator*(ll n){ if(n >= MOD) n %= MOD; return ModInt((v*n)%MOD); } ModInt operator/(ll n){ return ModInt((ModInt(n).inv()*v).v%MOD); } void operator+=(ll n){ v = (v+n)%MOD; } void operator-=(ll n){ v = (v-n+MOD)%MOD; } void operator*=(ll n){ v = (v*n+MOD)%MOD; } ModInt operator+(ModInt n){ return ModInt((v+n.v)%MOD); } ModInt operator-(ModInt n){ return ModInt((v-n.v+MOD)%MOD); } ModInt operator*(ModInt n){ return ModInt((v*n.v)%MOD); } ModInt operator/(ModInt n){ return ModInt((n.inv()*v).v%MOD); } void operator+=(ModInt n){ v = (v+n.v)%MOD; } void operator-=(ModInt n){ v = (v-n.v+MOD)%MOD; } void operator*=(ModInt n){ v = (v*n.v)%MOD; } void operator=(ModInt n){ v = n.v; } bool operator==(ModInt n){ return v == n.v; } bool operator!=(ModInt n){ return v != n.v; } void operator=(ll n){ v = n%MOD; } ModInt inv(){ if(v == 1) return ModInt(1); else return ModInt(MOD-ModInt(MOD%v).inv().v*(MOD/v)%MOD); } }; ostream& operator<<(ostream& os, const ModInt& m){ os << m.v; return os; } istream & operator >> (istream &in, ModInt &m){ in >> m.v; return in; } ModInt pow(ModInt a, ll n) { assert(n >= 0); ModInt ans = 1; ModInt tmp = a; for (int i = 0; i <= 60; i++) { ll m = (ll)1 << i; if (m & n) { ans *= tmp; } tmp *= tmp; } return ans; } #define N_MAX 2000002 ModInt inv[N_MAX],fac[N_MAX],finv[N_MAX]; void init(){ fac[0]=1;fac[1]=1; finv[0]=1;finv[1]=1; inv[1]=1; for(int i=2;i<N_MAX;i++){ inv[i]=ModInt(MOD)-inv[MOD%i]*(MOD/i); fac[i]=fac[i-1]*(ll) i; finv[i]=finv[i-1]*inv[i]; } } ModInt comb(ll n, ll r){ if(n < r){ return ModInt(0); }else{ return fac[n]*finv[r]*finv[n-r]; } } ModInt h(ll n, ll r){ if(n == 0 && r == 0) return ModInt(1); return comb(n+r-1, n-1); } using mint = ModInt; int main(){ ios::sync_with_stdio(false); cin.tie(0); cout << setprecision(10) << fixed; init(); int a, b, x, y; cin >> a >> b >> x >> y; vector<int> cnt(4, (b+1)/4); for(int i = 0; i < (b+1)%4; i++) cnt[i]++; int cnt_x = -1, cnt_y = -1; auto ng = [&](){ if(y > 0 && cnt[1] == 0) return true; if(x < 0 && cnt[2] == 0) return true; if(y < 0 && cnt[3] == 0) return true; return false; }; if(ng()){ cout << 0 << endl; return 0; } mint ans = 0; for(int cnt_x = abs(x); cnt_x+abs(y) <= a; cnt_x+=2){ int cnt_y = a-cnt_x; int ax = (cnt_x+x)/2, bx = (cnt_x-x)/2; mint tmp = 1; tmp *= h(cnt[0], ax)*h(cnt[2], bx); if(((cnt_y+y))%2 == 1) continue; int ay = (cnt_y+y)/2, by = (cnt_y-y)/2; tmp *= h(cnt[1], ay)*h(cnt[3], by); ans += tmp; } cout << ans << endl; }