#1192006 (C++23) No.3687 Coprime Count

• 問題: No.3687 Coprime Count
• ユーザー: kuromath
• 提出日時: 2026-10-08 23:50:51
• 言語: C++23 (gcc 15.3.0 + boost 1.92.0 + ACL)
• 結果: AC
• 実行時間: 431 ms / 2,000 ms
• コード長: 9,980 bytes
• コンパイル時間: 4,145 ms
• コンパイル使用メモリ: 377,132 KB
• 実行使用メモリ: 121,824 KB
• 最終ジャッジ日時: 2026-10-08 23:51:04
• 合計ジャッジ時間: 7,222 ms
• ジャッジサーバーID （参考情報）: judge4_0 / judge1_0

ファイルパターン	結果
sample	AC * 3
other	AC * 10

ソースコード

#include <bits/stdc++.h>
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
// using mint = modint1000000007;
#endif
//#pragma GCC target("avx2")
//#pragma GCC optimize("Ofast")
//#pragma GCC optimize("unroll-loops")
using namespace std;

inline void scan(int &a) { cin >> a; }
inline void scan(unsigned int &a) { cin >> a; }
inline void scan(long long &a) { cin >> a; }
inline void scan(unsigned long long &a) { cin >> a; }
inline void scan(float &a) { cin >> a; }
inline void scan(double &a) { cin >> a; }
inline void scan(long double &a) { cin >> a; }
inline void scan(char &a) { cin >> a; }
inline void scan(string &a) { cin >> a; }
inline void scan(vector<bool> &vec) { for (int i = 0; i < int(vec.size()); i++) { int a; scan(a); vec[i] = a; } }

template<typename T> inline void scan(vector<T> &vec);
template<typename T, size_t size> inline void scan(array<T, size> &vec);
template<typename T> inline void scan(deque<T> &deq);
template<typename T, typename U> inline void scan(pair<T, U> &p);

template<typename T> inline void scan(vector<T> &vec) { for (auto &i : vec) scan(i); }
template<typename T, size_t size> inline void scan(array<T, size> &vec) { for (auto &i : vec) scan(i); }
template<typename T> inline void scan(deque<T> &deq) { for (auto &i : deq) scan(i); }
template<typename T, typename U> inline void scan(pair<T, U> &p) { scan(p.first); scan(p.second); }
template<typename T> inline void scan(T &a) { cin >> a; }
inline void read() { }
template<typename T, typename... U> inline void read(T &a, U &...b) { scan(a); read(b...); }

inline void write(const int &a) { cout << a; }
inline void write(const unsigned int &a) { cout << a; }
inline void write(const long long &a) { cout << a; }
inline void write(const unsigned long long &a) { cout << a; }
inline void write(const float &a) { cout << a; }
inline void write(const double &a) { cout << a; }
inline void write(const long double &a) { cout << a; }
inline void write(const char &a) { cout << a; }
inline void write(const string &a) { cout << a; }

template<typename T> inline void write(const vector<T> &vec);
template<typename T, size_t size> inline void write(const array<T, size> &vec);
template<typename T> inline void write(const deque<T> &deq);
template<typename T, typename U> inline void write(const pair<T, U> &p);

template<typename T> inline void write(const vector<T> &vec) {
    for (int i = 0; i < int(vec.size()); i++) {
        if (i) write(' ');
        write(vec[i]);
    }
}

template<typename T, size_t size> inline void write(const array<T, size> &vec) {
    for (int i = 0; i < int(vec.size()); i++) {
        if (i) write(' ');
        write(vec[i]);
    }
}

template<typename T> inline void write(const deque<T> &deq) {
    for (int i = 0; i < int(deq.size()); i++) {
        if (i) write(' ');
        write(deq[i]);
    }
}

template<typename T, typename U> inline void write(const pair<T, U> &p) {
    write(p.first);
    write(' ');
    write(p.second);
}

template<typename T> inline void write(const T &a) { cout << a; }

inline void print() { cout << '\n'; }
template<typename T> inline void print(const T &a) { write(a); cout << '\n'; }
template<typename T, typename... U> inline void print(const T &a, const U &...b) {
    write(a);
    ((cout << ' ', write(b)), ...);
    write('\n');
}
template<typename T> inline void debug_impl(const char *name, const T &value) {
    cerr << name << " = ";
    write(value);
    cerr << '\n';
}

template<typename T, typename ... U> inline void debug_impl(const char *names, const T &value, const U &...values) {
    const char *comma = strchr(names, ',');
    cerr.write(names, comma - names);
    cerr << " = ";
    write(value);
    cerr << ", ";
    while (*++comma == ' ');
    debug_impl(comma, values...);
}

using ll = long long;
using ld = long double;
using ull = unsigned long long;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
template<typename T> using pq = priority_queue<T>;
template<typename T> using pq_g = priority_queue<T, vector<T>, greater<T>>;

#define overload3(a, b, c, d, ...) d
#define overload4(a, b, c, d, e, ...) e
#define rep1(n) for (ll i = 0; i < (n); i++)
#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(v) (v).begin(), (v).end()
#define all2(v, n) (v).begin(), (v).begin() + (n)
#define all3(v, a, b) (v).begin() + (a), (v).begin() + (b)
#define all(...) overload3(__VA_ARGS__, all3, all2, all1)(__VA_ARGS__)
#define rall(v) (v).rbegin(), (v).rend()
#define UNIQUE(v) (v).erase(unique((v).begin(), (v).end()), (v).end())
#define NP next_permutation
#define endl '\n'
#define INT(...) int __VA_ARGS__; read(__VA_ARGS__);
#define LL(...) long long __VA_ARGS__; read(__VA_ARGS__);
#define ULL(...) unsigned long long __VA_ARGS__; read(__VA_ARGS__);
#define STR(...) string __VA_ARGS__; read(__VA_ARGS__);
#define CHAR(...) char __VA_ARGS__; read(__VA_ARGS__);
#define LD(...) long double __VA_ARGS__; read(__VA_ARGS__);
#define VEC(type, name, size) vector<type> name(size); read(name);
#define VV(type, name, h, w) vector<vector<type>> name(h, vector<type>(w)); read(name);
#ifdef LOCAL
#define debug(...) debug_impl(#__VA_ARGS__, __VA_ARGS__)
#else
#define debug(...) ((void)0)
#endif

inline void Yes(bool a = true) { cout << (a ? "Yes" : "No") << endl; }
inline void No(bool a = true) { cout << (a ? "No" : "Yes") << endl; }
inline void YES(bool a = true) { cout << (a ? "YES" : "NO") << endl; }
inline void NO(bool a = true) { cout << (a ? "NO" : "YES") << endl; }
inline void Takahashi(bool a = true) { cout << (a ? "Takahashi" : "Aoki") << endl; }
inline void Alice(bool a = true) { cout << (a ? "Alice" : "Bob") << endl; }
inline void Possible(bool a = true) { cout << (a ? "Possible" : "Impossible") << endl; }

template<typename T, typename U>
auto operator+(const pair<T, U>& a, const pair<T, U>& b) { return pair<T, U>{a.first + b.first, a.second + b.second}; };
template <typename T, typename U>
auto operator-(const pair<T, U>& a, const pair<T, U>& b) { return pair<T, U>{a.first - b.first, a.second - b.second}; };

constexpr int INF = 1001001001;
constexpr ll LINF = 4004004004004004004LL;
constexpr ld pi = 3.14159265358979323846;
constexpr ld eps = 1e-9;
constexpr int dx[8] = { 1, 0, -1, 0, 1, -1, -1, 1 };
constexpr int dy[8] = { 0, 1, 0, -1, 1, 1, -1, -1 };

ll modPow(ll a, ll n, ll mod = LINF) { ll ret = 1; ll x = a % mod; while (n) { if (n & 1) ret = ret * x % mod; x = x * x % mod; n >>= 1; } return ret; }
int topbit(int x) { return (x == 0 ? -1 : 31 - __builtin_clz(x)); }
int topbit(ll x) { return (x == 0 ? -1 : 63 - __builtin_clzll(x)); }
int lowbit(int x) { return (x == 0 ? -1 : __builtin_ctz(x)); }
int lowbit(ll x) { return (x == 0 ? -1 : __builtin_ctz(x)); }
int popcount(int x) { return __builtin_popcount(x); }
ll popcount(ll x) { return __builtin_popcountll(x); }
ll isqrt(ll x) { ll n = sqrtl(x); while ((n + 1) * (n + 1) <= x) n++; while (n * n > x) n--; return n; }
template<typename T> T floor(T a, T b) { return a / b - (a % b && (a ^ b) < 0); }
template<typename T> T ceil(T a, T b) { return floor(a + b - 1, b); }
template<typename T> T bmod(T a, T b) { return a - b * floor(a, b); }
template<typename T> pair<T, T> divmod(T a, T b) { return { floor(a, b), a - b * floor(a, b) }; }
template<typename T> auto MIN(const vector<T> &a) { return *min_element(all(a)); }
template<typename T> auto MAX(const vector<T> &a) { return *max_element(all(a)); }
template<typename T> auto SUM(const vector<T> &a) { return accumulate(all(a), T(0)); }
template<typename T> bool chmin(T &a, const T &b) { if (a > b) { a = b; return true; } return false; }
template<typename T> bool chmax(T &a, const T &b) { if (a < b) { a = b; return true; } return false; }

void cincout() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(15);
}

struct Eratosthenes {
    vector<bool> isPrime;
    vector<int> minfactor;
    vector<int> mobius;

    Eratosthenes(int n) : isPrime(n + 1, true), minfactor(n + 1, -1), mobius(n + 1, 1) {
        isPrime[0] = isPrime[1] = false;
        minfactor[1] = 1;

        for (int i = 2; i <= n; i++) {
            if (!isPrime[i]) continue;
            minfactor[i] = i;
            mobius[i] = -1;
            for (int j = i * 2; j <= n; j += i) {
                isPrime[j] = false;
                if (minfactor[j] == -1) minfactor[j] = i;
                if ((j / i) % i == 0) mobius[j] = 0;
                else mobius[j] = -mobius[j];
            }
        }
    }

    vector<int> prime_table() {
        vector<int> Primes;
        for (int i = 2; i < int(isPrime.size()); i++) {
            if (isPrime[i]) Primes.push_back(i);
        }
        return Primes;
    }

    vector<int> mobius_table() {
        return mobius;
    }

    vector<pair<int, int>> factorize(int n) {
        vector<pair<int, int>> F;
        while (n > 1) {
            int p = minfactor[n];
            int ex = 0;
            while (n % p == 0) {
                n /= p;
                ex++;
            }
            F.emplace_back(p, ex);
        }
        return F;
    }
};

void solve() {
    INT(N, M);
    Eratosthenes E(min(N, M));
    auto mobius = E.mobius_table();
    ll ans = 0;
    for (int i = 1; i <= min(N, M); i++) ans += ll(mobius[i]) * floor(N, i) * floor(M / i);
    print(ans);
}

int main() {
    cincout();
    int t = 1;
    // cin >> t;
    while (t--) solve();
    return 0;
}