結果

問題 No.2480 Sequence Sum
ユーザー ecotteaecottea
提出日時 2023-09-22 21:33:18
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 4 ms / 500 ms
コード長 7,100 bytes
コンパイル時間 3,909 ms
コンパイル使用メモリ 256,828 KB
最終ジャッジ日時 2025-02-17 00:24:50
ジャッジサーバーID
(参考情報)
judge2 / judge2
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ファイルパターン 結果
sample AC * 2
other AC * 13
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ソースコード

diff #
プレゼンテーションモードにする

#ifndef HIDDEN_IN_VS //
//
#define _CRT_SECURE_NO_WARNINGS
//
#include <bits/stdc++.h>
using namespace std;
//
using ll = long long; // -2^63 2^63 = 9 * 10^18int -2^31 2^31 = 2 * 10^9
using pii = pair<int, int>; using pll = pair<ll, ll>; using pil = pair<int, ll>; using pli = pair<ll, int>;
using vi = vector<int>; using vvi = vector<vi>; using vvvi = vector<vvi>; using vvvvi = vector<vvvi>;
using vl = vector<ll>; using vvl = vector<vl>; using vvvl = vector<vvl>; using vvvvl = vector<vvvl>;
using vb = vector<bool>; using vvb = vector<vb>; using vvvb = vector<vvb>;
using vc = vector<char>; using vvc = vector<vc>; using vvvc = vector<vvc>;
using vd = vector<double>; using vvd = vector<vd>; using vvvd = vector<vvd>;
template <class T> using priority_queue_rev = priority_queue<T, vector<T>, greater<T>>;
using Graph = vvi; using ull = unsigned long long;
//
const double PI = acos(-1);
const vi DX = { 1, 0, -1, 0 }; // 4
const vi DY = { 0, 1, 0, -1 };
int INF = 1001001001; ll INFL = 4004004003104004004LL; // (int)INFL = 1010931620;
double EPS = 1e-15;
//
struct fast_io { fast_io() { cin.tie(nullptr); ios::sync_with_stdio(false); cout << fixed << setprecision(18); } } fastIOtmp;
//
#define all(a) (a).begin(), (a).end()
#define sz(x) ((int)(x).size())
#define lbpos(a, x) (int)distance((a).begin(), std::lower_bound(all(a), x))
#define ubpos(a, x) (int)distance((a).begin(), std::upper_bound(all(a), x))
#define Yes(b) {cout << ((b) ? "Yes\n" : "No\n");}
#define rep(i, n) for(int i = 0, i##_len = int(n); i < i##_len; ++i) // 0 n-1
#define repi(i, s, t) for(int i = int(s), i##_end = int(t); i <= i##_end; ++i) // s t
#define repir(i, s, t) for(int i = int(s), i##_end = int(t); i >= i##_end; --i) // s t
#define repe(v, a) for(const auto& v : (a)) // a
#define repea(v, a) for(auto& v : (a)) // a
#define repb(set, d) for(int set = 0; set < (1 << int(d)); ++set) // d
#define repp(a) sort(all(a)); for(bool a##_perm = true; a##_perm; a##_perm = next_permutation(all(a))) // a
#define smod(n, m) ((((n) % (m)) + (m)) % (m)) // mod
#define uniq(a) {sort(all(a)); (a).erase(unique(all(a)), (a).end());} //
#define EXIT(a) {cout << (a) << endl; exit(0);} //
#define inQ(x, y, u, l, d, r) ((u) <= (x) && (l) <= (y) && (x) < (d) && (y) < (r)) //
//
template <class T> inline ll pow(T n, int k) { ll v = 1; rep(i, k) v *= n; return v; }
template <class T> inline bool chmax(T& M, const T& x) { if (M < x) { M = x; return true; } return false; } // true
    
template <class T> inline bool chmin(T& m, const T& x) { if (m > x) { m = x; return true; } return false; } // true
    
template <class T> inline T get(T set, int i) { return (set >> i) & T(1); }
//
template <class T, class U> inline istream& operator>>(istream& is, pair<T, U>& p) { is >> p.first >> p.second; return is; }
template <class T> inline istream& operator>>(istream& is, vector<T>& v) { repea(x, v) is >> x; return is; }
template <class T> inline vector<T>& operator--(vector<T>& v) { repea(x, v) --x; return v; }
template <class T> inline vector<T>& operator++(vector<T>& v) { repea(x, v) ++x; return v; }
#endif //
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
#ifdef _MSC_VER
#include "localACL.hpp"
#endif
//using mint = modint1000000007;
using mint = modint998244353;
//using mint = modint; // mint::set_mod(m);
namespace atcoder {
inline istream& operator>>(istream& is, mint& x) { ll x_; is >> x_; x = x_; return is; }
inline ostream& operator<<(ostream& os, const mint& x) { os << x.val(); return os; }
}
using vm = vector<mint>; using vvm = vector<vm>; using vvvm = vector<vvm>; using vvvvm = vector<vvvm>;
#endif
#ifdef _MSC_VER // Visual Studio
#include "local.hpp"
#else // gcc
inline int popcount(int n) { return __builtin_popcount(n); }
inline int popcount(ll n) { return __builtin_popcountll(n); }
inline int lsb(int n) { return n != 0 ? __builtin_ctz(n) : -1; }
inline int lsb(ll n) { return n != 0 ? __builtin_ctzll(n) : -1; }
inline int msb(int n) { return n != 0 ? (31 - __builtin_clz(n)) : -1; }
inline int msb(ll n) { return n != 0 ? (63 - __builtin_clzll(n)) : -1; }
inline int msb(__int128 n) { return (n >> 64) != 0 ? (127 - __builtin_clzll((ll)(n >> 64))) : n != 0 ? (63 - __builtin_clzll((ll)(n))) : -1; }
#define gcd __gcd
#define dump(...)
#define dumpel(v)
#define dump_list(v)
#define dump_mat(v)
#define input_from_file(f)
#define output_to_file(f)
#define Assert(b) { if (!(b)) while (1) cout << "OLE"; }
#endif
//O(√n)
/*
* i=[1..n] n/i = q i [il..ir)
* {il, ir, q} il
* -q
*/
vector<tuple<ll, ll, ll>> quotient_range(ll n) {
// : https://ei1333.github.io/luzhiled/snippets/math/quotient-range.html
// verify : https://judge.yosupo.jp/problem/enumerate_quotients
//
// n/i q i i
// q = floor(n/i)
// ⇔ q ≦ n/i < q+1
// ⇔ i q ≦ n < i(q+1)
// ⇔ n/(q+1) < i ≦ n/q
//
//
// 1 q i 1
// n/q - n/(q+1) ≦ 1
// ⇔ (q+1)n - q n ≦ q(q+1)
// ⇔ n ≦ q(q+1)
//
// n ≦ q^2 ⇔ √n ≦ q
//
//
// n = 15
// i n/i n mod i
// [1..2) 15 [0]
// [2..3) 7 [1]
// [3..4) 5 [0]
// [4..6) 3 [3, 0]
// [6..8) 2 [3, 1]
// [8..16) 1 [7, 6, 5, 4, 3, 2, 1, 0]
ll m = (ll)(sqrt(n) + 1e-9);
vector<tuple<ll, ll, ll>> res;
res.reserve(n / (m + 1) + m);
// q i 1 i
repi(i, 1, n / (m + 1)) res.emplace_back(i, i + 1, n / i);
// q
ll il, ir = n / (m + 1) + 1;
repir(q, m, 1) {
il = ir;
ir = n / q + 1;
res.emplace_back(il, ir, q);
}
return res;
}
int main() {
// input_from_file("input.txt");
// output_to_file("output.txt");
ll n;
cin >> n;
auto qr = quotient_range(n);
int res = 0;
for (auto [il, ir, q] : qr) {
res += ir - il;
if (n % (ir - 1) == 0) res--;
}
cout << res << endl;
}
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