結果

問題 No.3307 Almost Equal
ユーザー 👑 potato167
提出日時 2025-10-05 14:37:25
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 2 ms / 2,000 ms
コード長 4,809 bytes
コンパイル時間 1,858 ms
コンパイル使用メモリ 199,564 KB
実行使用メモリ 7,716 KB
最終ジャッジ日時 2025-10-05 14:37:40
合計ジャッジ時間 3,352 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge4
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 * 3
other AC * 46
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 # 

#line 1 "a.cpp"
#include <bits/stdc++.h>
using namespace std;
using ll=__int128_t;
const ll ILL=2167167167167167167;
const int INF=2100000000;
#define rep(i,a,b) for (int i=(int)(a);i<(int)(b);i++)
#define all(p) p.begin(),p.end()
template<class T> using _pq = priority_queue<T, vector<T>, greater<T>>;
template<class T> int LB(vector<T> &v,T a){return lower_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> int UB(vector<T> &v,T a){return upper_bound(v.begin(),v.end(),a)-v.begin();}
template<class T> bool chmin(T &a,T b){if(b<a){a=b;return 1;}else return 0;}
template<class T> bool chmax(T &a,T b){if(a<b){a=b;return 1;}else return 0;}
template<class T> void So(vector<T> &v) {sort(v.begin(),v.end());}
template<class T> void Sore(vector<T> &v) {sort(v.begin(),v.end(),[](T x,T y){return x>y;});}
bool yneos(bool a,bool upp=false){if(a){cout<<(upp?"YES\n":"Yes\n");}else{cout<<(upp?"NO\n":"No\n");}return a;}
template<class T> void vec_out(vector<T> &p,int ty=0){
    if(ty==2){cout<<'{';for(int i=0;i<(int)p.size();i++){if(i){cout<<",";}cout<<'"'<<p[i]<<'"';}cout<<"}\n";}
    else{if(ty==1){cout<<p.size()<<"\n";}for(int i=0;i<(int)(p.size());i++){if(i) cout<<" ";cout<<p[i];}cout<<"\n";}}
template<class T> T vec_min(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmin(ans,x);return ans;}
template<class T> T vec_max(vector<T> &a){assert(!a.empty());T ans=a[0];for(auto &x:a) chmax(ans,x);return ans;}
template<class T> T vec_sum(vector<T> &a){T ans=T(0);for(auto &x:a) ans+=x;return ans;}
int pop_count(long long a){int res=0;while(a){res+=(a&1),a>>=1;}return res;}
template<class T> T square(T a){return a * a;}
#line 2 "/Users/Shared/po167_library/modint/mint61.hpp"

// https://qiita.com/keymoon/items/11fac5627672a6d6a9f6
namespace po167{
struct mint61{
    using u64 = unsigned long long;
    static constexpr u64 MOD = (1ULL << 61) - 1;
    static constexpr u64 MASK30 = (1ULL << 30) - 1;
    static constexpr u64 MASK31 = (1ULL << 31) - 1;
    u64  x;
    u64 calcmod(u64 a){
        u64 au = (a >> 61);
        u64 ad = (a & MOD);
        u64 res = au + ad;
        if (res >= MOD) res -= MOD;
        return res;
    }
    mint61(){ x = 0;}
    mint61(long long x_){
        while (x_ < 0) x_ += MOD;
        x = calcmod(x_);
    }
    mint61 &operator+=(mint61 b){
        if ((x += b.x) >= MOD) x -= MOD;
        return *this;
    }
    mint61 &operator-=(mint61 b){
        if (x >= b.x) x -= b.x;
        else{
            x += MOD;
            x -= b.x;
        }
        return *this;
    }
    mint61 &operator*=(mint61 b){
        u64 au = (x >> 31);
        u64 ad = (x & MASK31);
        u64 bu = (b.x >> 31);
        u64 bd = (b.x & MASK31);
        u64 mid = ad * bu + au * bd;
        u64 midu = (mid >> 30);
        u64 midd = (mid & MASK30);
        x = calcmod(au * bu * 2 + midu + (midd << 31) + ad * bd);
        return *this;
    }
    friend mint61 operator+(mint61 a, mint61 b){return a += b;}
    friend mint61 operator-(mint61 a, mint61 b){return a -= b;}
    friend mint61 operator*(mint61 a, mint61 b){return a *= b;}
    friend bool operator==(mint61 a, mint61 b){return a.x == b.x;}
    friend bool operator!=(mint61 a, mint61 b){return a.x != b.x;}
    mint61 pow(long long e) const {
        mint61 r = 1,b =*this;
        if (e < 0) e = MOD - 1 + e % (MOD - 1);
        while (e){
            if (e & 1) r *= b;
            b *= b;
            e >>= 1;
        }
        return r;
    }
};
}
#line 25 "a.cpp"
using mint = po167::mint61;
mint inv2 = (mint::MOD + 1) / 2;
//for(i=0;i<n)Σ(a*i+b)/m、(y=ax+bより下にある、0<=x<nかつy>0の格子点の数)
mint Fsum(ll n,ll m,ll a,ll b){
    mint ans=0;
    ans+=(mint(b/m))*n+(mint(a/m))*n*(n-1)*inv2;
    b%=m,a%=m;
    ll y=(a*(n-1)+b)/m;
    ll x=y*m-b;
    if(y==0){
        return ans;
    }
    ans+=(mint)(n-(x-1)/a-1)*y;
    ans+=Fsum(y,a,m,((x+a-1)/a)*a-x);
    return ans;
}
void solve();
// POP'N ROLL MUSIC / TOMOO
int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int t = 1;
    // cin >> t;
    rep(i, 0, t) solve();
}

void solve(){
    ll A, B, C, D;
    {
        int a, b, c, d;
        cin >> a >> b >> c >> d;
        A = a, B = b, C = c, D = d;
    }
    if (A * D > B * C) swap(A, C), swap(B, D);
    if (A * D == B * C){
        cout << "-1\n";
        return;
    }
    long lim = B * D / (B * C - A * D);
    // cerr << A << " " << B << " " << C << " " << D << " " << lim << "\n"
    mint ans = Fsum(lim, D * 2, C * 2, D);
    mint tmp = 0;
    // rep(i, 0, lim) tmp += (i * C * 2 + D) / (D * 2);
    cerr << tmp.x << " ";
    cerr << ans.x << " ";
    ans -= Fsum(lim, B * 2, A * 2, B);
    // rep(i, 0, lim) tmp -= (i * A * 2 + B) / (B * 2);
    cerr << tmp.x << " ";
    cerr << ans.x << "\n";
    cout << (lim - ans.x) - 1 << "\n";
}
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