結果
問題 | No.1918 Simple Math ? |
ユーザー |
![]() |
提出日時 | 2022-04-29 22:38:28 |
言語 | C++17 (gcc 13.3.0 + boost 1.87.0) |
結果 |
AC
|
実行時間 | 1,803 ms / 2,000 ms |
コード長 | 4,384 bytes |
コンパイル時間 | 1,600 ms |
コンパイル使用メモリ | 114,788 KB |
最終ジャッジ日時 | 2025-01-28 23:27:14 |
ジャッジサーバーID (参考情報) |
judge1 / judge3 |
(要ログイン)
ファイルパターン | 結果 |
---|---|
sample | AC * 1 |
other | AC * 33 |
ソースコード
#include <iostream> #include <algorithm> #include <iomanip> #include <vector> #include <queue> #include <deque> #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; template<typename T> vector<vector<T>> vec2d(int n, int m, T v){ return vector<vector<T>>(n, vector<T>(m, v)); } template<typename T> vector<vector<vector<T>>> vec3d(int n, int m, int k, T v){ return vector<vector<vector<T>>>(n, vector<vector<T>>(m, vector<T>(k, v))); } template<typename T> void print_vector(vector<T> v, char delimiter=' '){ if(v.empty()) { cout << endl; return; } for(int i = 0; i+1 < v.size(); i++) cout << v[i] << delimiter; cout << v.back() << endl; } 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); } ModInt &operator+=(ll n){ v = (v+n)%MOD; return *this; } ModInt &operator-=(ll n){ v = (v-n+MOD)%MOD; return *this; } ModInt &operator*=(ll n){ v = (v*n+MOD)%MOD; return *this; } 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); } ModInt &operator+=(ModInt n){ v = (v+n.v)%MOD; return *this; } ModInt &operator-=(ModInt n){ v = (v-n.v+MOD)%MOD; return *this; } ModInt &operator*=(ModInt n){ v = (v*n.v)%MOD; return *this; } bool operator==(ModInt n){ return v == n.v; } bool operator!=(ModInt n){ return v != n.v; } ModInt &operator=(ll n){ v = n%MOD; return *this; } 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; while (n > 0) { if (n&1) ans = ans*a; a = a*a; n >>= 1; } return ans; } using mint = ModInt; // calc ceil(a/b) template<typename T> T ceil_div(T a, T b){ return (a+b-1)/b; } mint calc_sum_square(ll n){ return mint((n*(n+1)*(2*n+1))/6); } mint calc_sum(ll n){ return mint((n*(n+1))/2); } void solve(){ ll a, n; cin >> a >> n; mint ans = 0; for(ll r = 0; r < a; r++){ ll extra = ceil_div(r*r, a); auto f = [&](ll x){ return a*x*x+2*x*r+extra; }; auto calc_rb = [&](){ ll l = 0, r = (1e6)+100; while(r-l > 1){ ll x = (l+r)/2; if(f(x) > n) r = x; else l = x; } return l; }; ll lb = r == 0 ? 1 : 0; if(f(lb) > n){ continue; } ll rb = calc_rb(); mint tmp = mint(rb-lb+1)*(n+1-extra); tmp -= calc_sum_square(rb)*a - calc_sum_square(lb-1)*a; tmp -= calc_sum(rb)*r*2 - calc_sum(lb-1)*r*2; ans += tmp; // cout << r << ' ' << tmp << endl; } cout << ans << endl; } int main(){ ios::sync_with_stdio(false); cin.tie(0); cout << setprecision(10) << fixed; int t; cin >> t; while(t--) solve(); }