結果

問題 No.1918 Simple Math ?
ユーザー milanis48663220milanis48663220
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
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 1
other AC * 33
権限があれば一括ダウンロードができます

ソースコード

diff #
プレゼンテーションモードにする

#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();
}
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