結果

問題 No.2645 Sum of Divisors?
ユーザー 👑 NachiaNachia
提出日時 2024-02-20 00:13:38
言語 C++17
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 66 ms / 2,000 ms
コード長 7,686 bytes
コンパイル時間 1,273 ms
コンパイル使用メモリ 114,404 KB
実行使用メモリ 99,244 KB
最終ジャッジ日時 2024-09-29 03:18:42
合計ジャッジ時間 3,431 ms
ジャッジサーバーID
（参考情報） 		judge1 / judge4
このコードへのチャレンジ
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テストケース

テストケース表示
入力 結果 実行時間
実行使用メモリ
testcase_00 AC 35 ms
81,656 KB
testcase_01 AC 34 ms
81,684 KB
testcase_02 AC 54 ms
97,940 KB
testcase_03 AC 36 ms
81,592 KB
testcase_04 AC 34 ms
81,556 KB
testcase_05 AC 33 ms
81,632 KB
testcase_06 AC 64 ms
99,244 KB
testcase_07 AC 66 ms
98,824 KB
testcase_08 AC 36 ms
81,560 KB
testcase_09 AC 33 ms
81,460 KB
testcase_10 AC 33 ms
81,620 KB
testcase_11 AC 34 ms
81,628 KB
testcase_12 AC 35 ms
81,520 KB
testcase_13 AC 34 ms
81,564 KB
testcase_14 AC 34 ms
81,740 KB
testcase_15 AC 33 ms
81,456 KB
testcase_16 AC 34 ms
81,740 KB
testcase_17 AC 33 ms
81,692 KB
testcase_18 AC 32 ms
81,624 KB
testcase_19 AC 33 ms
81,620 KB
testcase_20 AC 35 ms
82,080 KB
testcase_21 AC 34 ms
81,948 KB
testcase_22 AC 34 ms
82,196 KB
testcase_23 AC 35 ms
82,444 KB
testcase_24 AC 38 ms
83,600 KB
testcase_25 AC 38 ms
83,476 KB
testcase_26 AC 39 ms
83,860 KB
testcase_27 AC 41 ms
86,676 KB
testcase_28 AC 48 ms
90,244 KB
testcase_29 AC 64 ms
98,404 KB
testcase_30 AC 49 ms
89,824 KB
testcase_31 AC 58 ms
98,396 KB
testcase_32 AC 63 ms
98,304 KB
testcase_33 AC 49 ms
89,848 KB
testcase_34 AC 60 ms
99,160 KB
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 # 

#ifdef NACHIA
// #define _GLIBCXX_DEBUG
#else
#define NDEBUG
#endif
#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <queue>
#include <array>
#include <cmath>
#include <atcoder/modint>
using i64 = long long;
using u64 = unsigned long long;
#define rep(i,n) for(i64 i=0; i<(i64)(n); i++)
#define repr(i,n) for(i64 i=(i64)(n)-1; i>=0; i--)
const i64 INF = 1001001001001001001;
const char* yn(bool x){ return x ? "Yes" : "No"; }
template<typename A> void chmin(A& l, const A& r){ if(r < l) l = r; }
template<typename A> void chmax(A& l, const A& r){ if(l < r) l = r; }
template<typename A> using nega_queue = std::priority_queue<A,std::vector<A>,std::greater<A>>;
using Modint = atcoder::static_modint<998244353>;

#include <iterator>
#include <functional>

template<class Elem> struct vec;

template<class Iter>
struct seq_view{
    using Ref = typename std::iterator_traits<Iter>::reference;
    using Elem = typename std::iterator_traits<Iter>::value_type;
    Iter a, b;
    Iter begin() const { return a; }
    Iter end() const { return b; }
    int size() const { return (int)(b-a); }
    seq_view(Iter first, Iter last) : a(first), b(last) {}
    seq_view sort() const { std::sort(a, b); return *this; }
    Ref& operator[](int x){ return *(a+x); }
    template<class F = std::less<Elem>, class ret = vec<int>> ret sorti(F f = F()) const {
        ret x(size()); for(int i=0; i<size(); i++) x[i] = i;
        x().sort([&](int l, int r){ return f(a[l],a[r]); });
        return x;
    }
    template<class ret = vec<Elem>> ret col() const { return ret(begin(), end()); }
    template<class F = std::equal_to<Elem>, class ret = vec<std::pair<Elem, int>>>
    ret rle(F eq = F()) const {
        auto x = ret();
        for(auto& a : (*this)){
            if(x.size() == 0 || !eq(x[x.size()-1].first, a)) x.emp(a, 1); else x[x.size()-1].second++;
        } return x;
    }
    template<class F> seq_view sort(F f) const { std::sort(a, b, f); return *this; }
    Iter uni() const { return std::unique(a, b); }
    Iter lb(const Elem& x) const { return std::lower_bound(a, b, x); }
    Iter ub(const Elem& x) const { return std::upper_bound(a, b, x); }
    int lbi(const Elem& x) const { return lb(x) - a; }
    int ubi(const Elem& x) const { return ub(x) - a; }
    seq_view bound(const Elem& l, const Elem& r) const { return { lb(l), lb(r) }; }
    template<class F> Iter lb(const Elem& x, F f) const { return std::lower_bound(a, b, x, f); }
    template<class F> Iter ub(const Elem& x, F f) const { return std::upper_bound(a, b, x, f); }
    template<class F> Iter when_true_to_false(F f) const {
        if(a == b) return a;
        return std::lower_bound(a, b, *a,
            [&](const Elem& x, const Elem&){ return f(x); });
    }
    seq_view same(Elem x) const { return { lb(x), ub(x) }; }
    template<class F> auto map(F f) const {
        vec<typename Iter::value_type> r;
        for(auto& x : *this) r.emp(f(x));
        return r;
    }
    Iter max() const { return std::max_element(a, b); }
    Iter min() const { return std::min_element(a, b); }
    template<class F = std::less<Elem>>
    Iter min(F f) const { return std::min_element(a, b, f); }
    seq_view rev() const { std::reverse(a, b); return *this; }
};

template<class Elem>
struct vec {
    using Base = typename std::vector<Elem>;
    using Iter = typename Base::iterator;
    using CIter = typename Base::const_iterator;
    using View = seq_view<Iter>;
    using CView = seq_view<CIter>;

    vec(){}
    explicit vec(int n, const Elem& value = Elem()) : a(0<n?n:0, value) {}
    template <class I2> vec(I2 first, I2 last) : a(first, last) {}
    vec(std::initializer_list<Elem> il) : a(std::move(il)) {}
    vec(Base b) : a(std::move(b)) {}
    operator Base() const { return a; }

    Iter begin(){ return a.begin(); }
    CIter begin() const { return a.begin(); }
    Iter end(){ return a.end(); }
    CIter end() const { return a.end(); }
    int size() const { return a.size(); }
    bool empty() const { return a.empty(); }
    Elem& back(){ return a.back(); }
    const Elem& back() const { return a.back(); }
    vec sortunied(){ vec x = *this; x().sort(); x.a.erase(x().uni(), x.end()); return x; }
    Iter operator()(int x){ return a.begin() + x; }
    CIter operator()(int x) const { return a.begin() + x; }
    View operator()(int l, int r){ return { (*this)(l), (*this)(r) }; }
    CView operator()(int l, int r) const { return { (*this)(l), (*this)(r) }; }
    View operator()(){ return (*this)(0,size()); }
    CView operator()() const { return (*this)(0,size()); }
    Elem& operator[](int x){ return a[x]; }
    const Elem& operator[](int x) const { return a[x]; }
    Base& operator*(){ return a; }
    const Base& operator*() const { return a; }
    vec& push(Elem args){
        a.push_back(std::move(args));
        return *this;
    }
    template<class... Args>
    vec& emp(Args &&... args){
        a.emplace_back(std::forward<Args>(args) ...);
        return *this;
    }
    template<class Range>
    vec& app(Range& x){ for(auto& v : a) emp(v); }
    Elem pop(){
        Elem x = std::move(a.back());
        a.pop_back(); return x;
    }
    bool operator==(const vec& r) const { return a == r.a; }
    bool operator!=(const vec& r) const { return a != r.a; }
    bool operator<(const vec& r) const { return a < r.a; }
    bool operator<=(const vec& r) const { return a <= r.a; }
    bool operator>(const vec& r) const { return a > r.a; }
    bool operator>=(const vec& r) const { return a >= r.a; }
    vec<vec<Elem>> pile(int n) const { return vec<vec<Elem>>(n, *this); }
    template<class F> vec& filter(F f){
        int p = 0;
        for(int q=0; q<size(); q++) if(f(a[q])) std::swap(a[p++],a[q]);
        a.resize(p); return *this;
    }
private: Base a;
};

template<class IStr, class U, class T>
IStr& operator>>(IStr& is, vec<std::pair<U,T>>& v){ for(auto& x:v){ is >> x.first >> x.second; } return is; }
template<class IStr, class T>
IStr& operator>>(IStr& is, vec<T>& v){ for(auto& x:v){ is >> x; } return is; }
template<class OStr, class T>
OStr& operator<<(OStr& os, const vec<T>& v){
    for(int i=0; i<v.size(); i++){
        if(i){ os << ' '; } os << v[i];
    } return os;
}
template<class OStr, class U, class T>
OStr& operator<<(OStr& os, const vec<std::pair<U,T>>& v){
    for(int i=0; i<v.size(); i++){
        if(i){ os << ' '; } os << '(' << v[i].first << ',' << v[i].second << ')';
    } return os;
}

namespace nachia{

template<class Int = long long>
std::vector<Int> EnumerateQuotients(Int N, bool doInsertZero){
    std::vector<Int> res;
    if(doInsertZero) res.push_back(0);
    Int f = 1;
    for( ; f*f<N; f++) res.push_back(f);
    int qp1 = res.size();
    for(Int k=1; k*f<=N; k++){
        res.push_back((k&1) ? (N/k) : (res[qp1+k/2-1]/2));
    }
    std::reverse(res.begin() + qp1, res.end());
    return res;
}

}
using namespace std;

void testcase(){
    i64 N; cin >> N;
    i64 Q = 10000000;
    vec<double> h(Q+1);
    rep(i,Q) h[i+1] = h[i] + 1.0 / double(i+1);
    double gammaConstant = 0.577215664901532;
    auto H = [&](i64 x) -> double {
        if(x <= Q) return h[x];
        return log(x) + gammaConstant;
    };
    auto quot = nachia::EnumerateQuotients(N, true);
    int qn = quot.size();
    double ans = 0;
    for(int i=1; i<qn; i++){
        ans += H(quot[i]) * (H(quot[qn-i]) - H(quot[qn-i-1]));
    }
    cout.precision(10); fixed(cout);
    cout << ans << endl;
}

int main(){
    ios::sync_with_stdio(false); cin.tie(nullptr);
    #ifdef NACHIA
    int T; cin >> T; for(int t=0; t<T; T!=++t?(cout<<'\n'),0:0)
    #endif
    testcase();
    return 0;
}
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