結果

問題 No.2847 Birthday Attack
コンテスト
ユーザー siganai
提出日時 2024-08-24 00:49:10
言語 C++23
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 2,487 ms / 3,000 ms
コード長 10,256 bytes
コンパイル時間 3,045 ms
コンパイル使用メモリ 261,216 KB
実行使用メモリ 18,896 KB
最終ジャッジ日時 2024-08-24 00:49:37
合計ジャッジ時間 25,025 ms
ジャッジサーバーID
（参考情報） 		judge3 / judge1
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 * 4
other AC * 14
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 "main.cpp"
#include<bits/stdc++.h>
using namespace std;
#pragma GCC target("avx,avx2")
#pragma GCC optimize("O3")
#pragma GCC optimize("unroll-loops")
#ifdef LOCAL
#include <debug.hpp>
#define debug(...) debug_print::multi_print(#__VA_ARGS__, __VA_ARGS__)
#else
#define debug(...) (static_cast<void>(0))
#endif
using namespace std;
using ll = long long;
using ull = unsigned long long;
using ld = long double;
using pll = pair<ll,ll>;
using pii = pair<int,int>;
using vi = vector<int>;
using vvi = vector<vi>;
using vvvi = vector<vvi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vvvl = vector<vvl>;
using vul = vector<ull>;
using vpii = vector<pii>;
using vvpii = vector<vpii>;
using vpll = vector<pll>;
using vs = vector<string>;
template<class T> using pq = priority_queue<T,vector<T>, greater<T>>;
#define overload4(_1, _2, _3, _4, name, ...) name
#define overload3(a,b,c,name,...) name
#define rep1(n) for (ll UNUSED_NUMBER = 0; UNUSED_NUMBER < (n); ++UNUSED_NUMBER)
#define rep2(i, n) for (ll i = 0; i < (n); ++i)
#define rep3(i, a, b) for (ll i = (a); i < (b); ++i)
#define rep4(i, a, b, c) for (ll i = (a); i < (b); i += (c))
#define rep(...) overload4(__VA_ARGS__, rep4, rep3, rep2, rep1)(__VA_ARGS__)
#define rrep1(n) for(ll i = (n) - 1;i >= 0;i--)
#define rrep2(i,n) for(ll i = (n) - 1;i >= 0;i--)
#define rrep3(i,a,b) for(ll i = (b) - 1;i >= (a);i--)
#define rrep4(i,a,b,c) for(ll i = (a) + ((b)-(a)-1) / (c) * (c);i >= (a);i -= c)
#define rrep(...) overload4(__VA_ARGS__, rrep4, rrep3, rrep2, rrep1)(__VA_ARGS__)
#define all1(i) begin(i) , end(i)
#define all2(i,a) begin(i) , begin(i) + a
#define all3(i,a,b) begin(i) + a , begin(i) + b
#define all(...) overload3(__VA_ARGS__, all3, all2, all1)(__VA_ARGS__)
#define sum(...) accumulate(all(__VA_ARGS__),0LL)
template<class T> bool chmin(T &a, const T &b){ if(a > b){ a = b; return 1; } else return 0; }
template<class T> bool chmax(T &a, const T &b){ if(a < b){ a = b; return 1; } else return 0; }
template<class T> auto min(const T& a){return *min_element(all(a));}
template<class T> auto max(const T& a){return *max_element(all(a));}
template<class... Ts> void in(Ts&... t);
#define INT(...) int __VA_ARGS__; in(__VA_ARGS__)
#define LL(...) ll __VA_ARGS__; in(__VA_ARGS__)
#define STR(...) string __VA_ARGS__; in(__VA_ARGS__)
#define CHR(...) char __VA_ARGS__; in(__VA_ARGS__)
#define DBL(...) double __VA_ARGS__; in(__VA_ARGS__)
#define LD(...) ld __VA_ARGS__; in(__VA_ARGS__)
#define VEC(type, name, size) vector<type> name(size); in(name)
#define VV(type, name, h, w) vector<vector<type>> name(h, vector<type>(w)); in(name)
ll intpow(ll a, ll b){ll ans = 1; while(b){if(b & 1) ans *= a; a *= a; b /= 2;} return ans;}
ll modpow(ll a, ll b, ll p){ ll ans = 1; a %= p;if(a < 0) a += p;while(b){ if(b & 1) (ans *= a) %= p; (a *= a) %= p; b /= 2; } return ans; }
bool is_clamp(ll val,ll low,ll high) {return low <= val && val < high;}
void Yes() {cout << "Yes\n";return;}
void No() {cout << "No\n";return;}
void YES() {cout << "YES\n";return;}
void NO() {cout << "NO\n";return;}
template <typename T>
T floor(T a, T b) {return a / b - (a % b && (a ^ b) < 0);}
template <typename T>
T ceil(T x, T y) {return floor(x + y - 1, y);}
template <typename T>
T bmod(T x, T y) {return x - y * floor(x, y);}
template <typename T>
pair<T, T> divmod(T x, T y) {T q = floor(x, y);return {q, x - q * y};}
namespace IO{
#define VOID(a) decltype(void(a))
struct setting{ setting(){cin.tie(nullptr); ios::sync_with_stdio(false);fixed(cout); cout.precision(15);}} setting;
template<int I> struct P : P<I-1>{};
template<> struct P<0>{};
template<class T> void i(T& t){ i(t, P<3>{}); }
void i(vector<bool>::reference t, P<3>){ int a; i(a); t = a; }
template<class T> auto i(T& t, P<2>) -> VOID(cin >> t){ cin >> t; }
template<class T> auto i(T& t, P<1>) -> VOID(begin(t)){ for(auto&& x : t) i(x); }
template<class T, size_t... idx> void ituple(T& t, index_sequence<idx...>){in(get<idx>(t)...);}
template<class T> auto i(T& t, P<0>) -> VOID(tuple_size<T>{}){ituple(t, make_index_sequence<tuple_size<T>::value>{});} 
#undef VOID
}
#define unpack(a) (void)initializer_list<int>{(a, 0)...}
template<class... Ts> void in(Ts&... t){ unpack(IO :: i(t)); }
#undef unpack
constexpr long double PI = 3.141592653589793238462643383279L;
template <class F> struct REC {
    F f;
    REC(F &&f_) : f(forward<F>(f_)) {}
    template <class... Args> auto operator()(Args &&...args) const { return f(*this, forward<Args>(args)...); }};

//constexpr int mod = 998244353;
constexpr int mod = 1000000007;
#line 2 "library/modint/barrett-reduction.hpp"
struct Barrett {
    using u32 = unsigned int;
    using i64 = long long;
    using u64 = unsigned long long;
    u32 m;
    u64 im;
    Barrett() : m(), im() {}
    Barrett(int n) : m(n), im(u64(-1) / m + 1) {}
    constexpr inline i64 quo(u64 n) {
        u64 x = u64((__uint128_t(n) * im) >> 64);
        u32 r = n - x * m;
        return m <= r ? x - 1 : x;
    }
    constexpr inline i64 rem(u64 n) {
        u64 x = u64((__uint128_t(n) * im) >> 64);
        u32 r = n - x * m;
        return m <= r ? r + m : r;
    }
    constexpr inline pair<i64, int> quorem(u64 n) {
        u64 x = u64((__uint128_t(n) * im) >> 64);
        u32 r = n - x * m;
        if (m <= r) return {x - 1, r + m};
        return {x, r};
    }
    constexpr inline i64 pow(u64 n, i64 p) {
        u32 a = rem(n), r = m == 1 ? 0 : 1;
        while (p) {
            if (p & 1) r = rem(u64(r) * a);
            a = rem(u64(a) * a);
            p >>= 1;
        }
        return r;
    }
};
#line 3 "library/modint/ArbitaryModint.hpp"
struct ArbitraryModint {
    int x;
    ArbitraryModint():x(0) {}
    ArbitraryModint(int64_t y) {
        int z = y % get_mod();
        if(z < 0) z += get_mod();
        x = z;
    }
    ArbitraryModint &operator+=(const ArbitraryModint &p) {
        if((x += p.x) >= get_mod()) x -= get_mod();
        return *this;
    }
    ArbitraryModint &operator-=(const ArbitraryModint &p) {
        if((x += get_mod() - p.x) >= get_mod()) x -= get_mod();
        return *this;
    }
    ArbitraryModint &operator*=(const ArbitraryModint &p) {
        x = rem((unsigned long long)x * p.x);
        return *this;
    }
    ArbitraryModint &operator/=(const ArbitraryModint &p) {
        *this *= p.inverse();
        return *this;
    }
    ArbitraryModint operator-() const {return ArbitraryModint(-x);};
    ArbitraryModint operator+(const ArbitraryModint &p) const{
        return ArbitraryModint(*this) += p;
    }
    ArbitraryModint operator-(const ArbitraryModint &p) const{
        return ArbitraryModint(*this) -= p;
    }
    ArbitraryModint operator*(const ArbitraryModint &p) const{
        return ArbitraryModint(*this) *= p;
    }
    ArbitraryModint operator/(const ArbitraryModint &p) const {
        return ArbitraryModint(*this) /= p;
    }
    bool operator==(const ArbitraryModint &p) {return x == p.x;}
    bool operator!=(const ArbitraryModint &p) {return x != p.x;}
    ArbitraryModint inverse() const {
        int a = x,b = get_mod(),u = 1,v = 0,t;
        while(b > 0) {
            t = a / b;
            swap(a -= t * b,b);
            swap(u -= t * v,v);
        }
        return ArbitraryModint(u);
    }
    ArbitraryModint pow(int64_t n) const {
        ArbitraryModint ret(1),mul(x);
        while(n > 0) {
            if(n & 1) ret *= mul;
            mul *= mul;
            n >>= 1;
        }
        return ret;
    }
    friend ostream &operator<<(ostream &os,const ArbitraryModint &p) {
        return os << p.x;
    }
    friend istream &operator>>(istream &is,ArbitraryModint &a) {
        int64_t t;
        is >> t;
        a = ArbitraryModint(t);
        return (is);
    }
    int get() const {return x;}
    inline unsigned int rem(unsigned long long p) {return barrett().rem(p);};
    static inline Barrett &barrett() {
        static Barrett b;
        return b;
    }
    static inline int &get_mod() {
        static int mod = 0;
        return mod;
    }
    static void set_mod(int md) {
        assert(0 < md && md <= (1LL << 30) - 1);
        get_mod() = md;
        barrett() = Barrett(md);
    }
};
#line 100 "main.cpp"
using mint = ArbitraryModint;
using vm = vector<mint>;
using vvm = vector<vm>;
using vvvm = vector<vvm>;
const int M = 4000000;
vi D(M+1);
vl make_divisor(vpii pr,ll ma) {
    ll ma2 = ma * ma;
    int n = pr.size();
    vl ret;
    auto dfs = REC([&](auto &&f,int id,ll tmp) -> void {
        if(id == n) {
            ret.emplace_back(tmp);
            return;
        }
        if(id == 0 && pr[id].first == 2) {
          ll C = 2;
          rep(i,pr[id].second-1) {
              if(tmp * C >= ma) return;
              f(id+1,tmp * C);
              C *= pr[id].first;
          }
        }
        else {
          ll C = 1;
          rep(i,pr[id].second+1) {
              if(tmp * C >= ma) return;
              f(id+1,tmp * C);
              C *= pr[id].first;
          }
        }
    });
    dfs(0,1);
    //sort(all(ret));
    return ret;
}
void solve() {
    INT(x,y,m);
    mint::set_mod(m);
    mint ans;
    rep(i,1,(x+1)/2) {
        ans += mint(y) * (x-2*i);
    }
    rep(i,1,(y+1)/2) {
        ans += mint(x) * (y-2*i);
    }
    int c = 0;
    int mx = (max(x,y)+1)/2;
    rep(i,2,mx) {
        vpii pr;
        int now = i;
        while(now > 1) {
            if(pr.empty() || pr.back().first != D[now]) {
                pr.emplace_back(D[now],2);
            }
            else pr.back().second += 2;
            now /= D[now];
        }
        auto di = make_divisor(pr,i);
        //auto d2 = divisor(i*i);
        for(auto &X:di) {
            ll Y = i * i / X;
            ll d = (Y - X) / 2;
            if(i > d) continue;
            //debug(i,d,x,y);
            if(2 * i < x && 2 * d < y) {
                c++;
                ans += mint(x-2*i) * mint(y-2*d) * 2;
            }
            if(2 * i < y && 2 * d < x) {
                ans += mint(y-2*i) * mint(x-2*d) * 2;
            }
        }
    }
    debug(c);
    ans *= 2;
    cout << ans << '\n';
}
int main() {
    //INT(TT);
    int TT = 1;
    rep(i,2,M+1) {
        if(D[i] == 0) {
            rep(j,i,M+1,i) if(D[j] == 0) D[j] = i;
        }
    }
    
    while(TT--) solve();
}
0