#572487 (C++14) No.1276 3枚のカード

• 問題: No.1276 3枚のカード
• ユーザー: logx
• 提出日時: 2020-10-30 20:58:59
• 言語: C++14 (gcc 12.3.0 + boost 1.83.0)
• 結果: AC
• 実行時間: 343 ms / 2,000 ms
• コード長: 2,545 bytes
• コンパイル時間: 1,712 ms
• コンパイル使用メモリ: 169,020 KB
• 実行使用メモリ: 5,376 KB
• 最終ジャッジ日時: 2024-07-21 23:03:07
• 合計ジャッジ時間: 12,779 ms
• ジャッジサーバーID （参考情報）: judge1 / judge3

入力	結果	実行時間; 実行使用メモリ
testcase_00	AC	2 ms; 5,248 KB
testcase_01	AC	2 ms; 5,376 KB
testcase_02	AC	2 ms; 5,376 KB
testcase_03	AC	2 ms; 5,376 KB
testcase_04	AC	1 ms; 5,376 KB
testcase_05	AC	2 ms; 5,376 KB
testcase_06	AC	2 ms; 5,376 KB
testcase_07	AC	2 ms; 5,376 KB
testcase_08	AC	2 ms; 5,376 KB
testcase_09	AC	2 ms; 5,376 KB
testcase_10	AC	288 ms; 5,376 KB
testcase_11	AC	138 ms; 5,376 KB
testcase_12	AC	174 ms; 5,376 KB
testcase_13	AC	184 ms; 5,376 KB
testcase_14	AC	18 ms; 5,376 KB
testcase_15	AC	150 ms; 5,376 KB
testcase_16	AC	314 ms; 5,376 KB
testcase_17	AC	167 ms; 5,376 KB
testcase_18	AC	128 ms; 5,376 KB
testcase_19	AC	211 ms; 5,376 KB
testcase_20	AC	124 ms; 5,376 KB
testcase_21	AC	130 ms; 5,376 KB
testcase_22	AC	328 ms; 5,376 KB
testcase_23	AC	15 ms; 5,376 KB
testcase_24	AC	200 ms; 5,376 KB
testcase_25	AC	66 ms; 5,376 KB
testcase_26	AC	247 ms; 5,376 KB
testcase_27	AC	287 ms; 5,376 KB
testcase_28	AC	269 ms; 5,376 KB
testcase_29	AC	156 ms; 5,376 KB
testcase_30	AC	32 ms; 5,376 KB
testcase_31	AC	15 ms; 5,376 KB
testcase_32	AC	72 ms; 5,376 KB
testcase_33	AC	5 ms; 5,376 KB
testcase_34	AC	50 ms; 5,376 KB
testcase_35	AC	47 ms; 5,376 KB
testcase_36	AC	5 ms; 5,376 KB
testcase_37	AC	43 ms; 5,376 KB
testcase_38	AC	29 ms; 5,376 KB
testcase_39	AC	74 ms; 5,376 KB
testcase_40	AC	310 ms; 5,376 KB
testcase_41	AC	257 ms; 5,376 KB
testcase_42	AC	275 ms; 5,376 KB
testcase_43	AC	236 ms; 5,376 KB
testcase_44	AC	343 ms; 5,376 KB
testcase_45	AC	300 ms; 5,376 KB
testcase_46	AC	308 ms; 5,376 KB
testcase_47	AC	251 ms; 5,376 KB
testcase_48	AC	240 ms; 5,376 KB
testcase_49	AC	269 ms; 5,376 KB
testcase_50	AC	302 ms; 5,376 KB
testcase_51	AC	257 ms; 5,376 KB
testcase_52	AC	222 ms; 5,376 KB
testcase_53	AC	264 ms; 5,376 KB
testcase_54	AC	302 ms; 5,376 KB
testcase_55	AC	230 ms; 5,376 KB
testcase_56	AC	231 ms; 5,376 KB
testcase_57	AC	288 ms; 5,376 KB
testcase_58	AC	303 ms; 5,376 KB
testcase_59	AC	261 ms; 5,376 KB
testcase_60	AC	340 ms; 5,376 KB

ソースコード

#include <bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define rep2(i, s, n) for (int i = s; i < (int)(n); i++)
typedef long long ll;

template <ll mod> struct Fp{
    ll x;
    constexpr Fp(ll x=0) noexcept : x ((x%mod+mod)%mod){}
    constexpr Fp operator-() const noexcept{return Fp(-x);}
    constexpr Fp& operator+=(const Fp &a) noexcept{if((x+=a.x)>=mod)x-=mod;return *this;}
    constexpr Fp& operator-=(const Fp &a) noexcept{if((x+=mod-a.x)>=mod)x-=mod;return *this;}
    constexpr Fp& operator*=(const Fp &a) noexcept{(x*=a.x)%=mod;return *this;}
    constexpr Fp& operator/=(const Fp &a) noexcept{return (*this)*=a.inv();}
    constexpr Fp operator+(const Fp &a)const noexcept{Fp res(*this);return res+=a;}
    constexpr Fp operator-(const Fp &a)const noexcept{Fp res(*this);return res-=a;}
    constexpr Fp operator*(const Fp &a)const noexcept{Fp res(*this);return res*=a;}
    constexpr Fp operator/(const Fp &a)const noexcept{Fp res(*this);return res/=a;}
    constexpr Fp inv()const noexcept{return (Fp)forinv((*this).x,mod).first;}
    friend ostream& operator<<(ostream &os,const Fp &m)noexcept{os << m.x;return os;}
    friend istream& operator>>(istream &is,Fp &m)noexcept{is >> m.x;m.x%=mod;if(m.x<0)m.x+=mod;return is;}
    constexpr pair<ll,ll> forinv(ll a,ll b)const noexcept{
        if(b==0)return pair<ll,ll>(1,0);
        pair<ll,ll> cnt1 = forinv(b,a%b);
        pair<ll,ll> t=pair<ll,ll>(cnt1.second,cnt1.first-a/b*cnt1.second);
        return t;
    }
};
const ll mod=1000000007LL;
using mint=Fp<mod>;

ll undersqrt(ll a){//[sqrt(a)]を返す
    ll under=-1;
    ll over=a+1;
    while(over-under>1){
        ll mid=(under+over)/2;
        if(mid*mid<=a)under=mid;
        else over=mid;
    }
    return under;
}

mint solve(ll a){
    mint cnt1=0;
    ll rt=undersqrt(a);
    rep(i,rt)cnt1+=a/(i+1);
    return cnt1*2-rt*rt;
}

int main(){
    ll n;cin >> n;
    ll rt = undersqrt(n);

    mint cnt1=0;
    rep2(i,1,rt+1){
        cnt1 += solve(n/i);
        cnt1 += solve(i) * (n/i-n/(i+1));
    }
    if(rt * (rt+1) > n)cnt1 -= solve(rt);
    cnt1 += -solve(n)*2 + n;

    mint cnt2=0;
    rep2(i,1,rt+1)cnt2 += (mint)(n/i-1)*(n/i-2) + (i-1)*(i-2)*(n/i-n/(i+1));
    if(rt*(rt+1)>n)cnt2 -= (rt-1)*(rt-2);
    cnt2 -= cnt1*2;

    mint cnt3=0;
    rep2(i,1,rt+1)cnt3 += (n - 2)*(n/i - 1) + (n-2) * (i-1) * (n/i - n/(i+1));
    if(rt*(rt+1)>n)cnt3 -= (n-2) * (rt-1);

    mint sum = cnt3 - cnt1*3 - cnt2;
    cout << sum << endl;

    assert(3LL<=n&&n<=2000000000LL);
}