結果

問題 No.2337 Equidistant
ユーザー 👑 rin204rin204
提出日時 2023-06-02 22:14:10
言語 C++23
(gcc 12.3.0 + boost 1.83.0)
結果
AC  
実行時間 759 ms / 4,000 ms
コード長 11,530 bytes
コンパイル時間 3,449 ms
コンパイル使用メモリ 263,232 KB
実行使用メモリ 38,424 KB
最終ジャッジ日時 2023-08-28 03:53:12
合計ジャッジ時間 12,412 ms
ジャッジサーバーID
（参考情報） 		judge15 / judge14
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 1 ms
4,380 KB
testcase_01 AC 2 ms
4,376 KB
testcase_02 AC 1 ms
4,376 KB
testcase_03 AC 2 ms
4,380 KB
testcase_04 AC 2 ms
4,376 KB
testcase_05 AC 2 ms
4,376 KB
testcase_06 AC 3 ms
4,376 KB
testcase_07 AC 3 ms
4,376 KB
testcase_08 AC 3 ms
4,376 KB
testcase_09 AC 4 ms
4,376 KB
testcase_10 AC 3 ms
4,380 KB
testcase_11 AC 338 ms
30,704 KB
testcase_12 AC 342 ms
30,552 KB
testcase_13 AC 345 ms
30,644 KB
testcase_14 AC 340 ms
30,640 KB
testcase_15 AC 318 ms
30,768 KB
testcase_16 AC 326 ms
30,624 KB
testcase_17 AC 340 ms
30,628 KB
testcase_18 AC 317 ms
30,640 KB
testcase_19 AC 336 ms
30,664 KB
testcase_20 AC 333 ms
30,708 KB
testcase_21 AC 402 ms
38,424 KB
testcase_22 AC 268 ms
31,960 KB
testcase_23 AC 274 ms
31,436 KB
testcase_24 AC 637 ms
35,740 KB
testcase_25 AC 303 ms
31,524 KB
testcase_26 AC 759 ms
35,752 KB
testcase_27 AC 325 ms
31,504 KB
testcase_28 AC 315 ms
31,716 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 # 

// start A.cpp
// #pragma GCC target("avx2")
// #pragma GCC optimize("O3")
// #pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
using namespace std;

using ll  = long long;
using ull = unsigned long long;
template <class T>
using pq = priority_queue<T>;
template <class T>
using qp = priority_queue<T, vector<T>, greater<T>>;
#define vec(T, A, ...) vector<T> A(__VA_ARGS__);
#define vvec(T, A, h, ...) vector<vector<T>> A(h, vector<T>(__VA_ARGS__));
#define vvvec(T, A, h1, h2, ...) vector<vector<vector<T>>> A(h1, vector<vector<T>>(h2, vector<T>(__VA_ARGS__)));

#ifndef RIN__LOCAL
#define endl "\n"
#endif
#define spa ' '
#define len(A) A.size()
#define all(A) begin(A), end(A)

#define fori1(a) for (ll _ = 0; _ < (a); _++)
#define fori2(i, a) for (ll i = 0; i < (a); i++)
#define fori3(i, a, b) for (ll i = (a); i < (b); i++)
#define fori4(i, a, b, c) for (ll i = (a); ((c) > 0 || i > (b)) && ((c) < 0 || i < (b)); i += (c))
#define overload4(a, b, c, d, e, ...) e
#define fori(...) overload4(__VA_ARGS__, fori4, fori3, fori2, fori1)(__VA_ARGS__)

vector<char> stoc(string &S) {
    int n = S.size();
    vector<char> ret(n);
    for (int i = 0; i < n; i++) ret[i] = S[i];
    return ret;
}

#define INT(...)                                                                                                                                                                                       \
    int __VA_ARGS__;                                                                                                                                                                                   \
    inp(__VA_ARGS__);
#define LL(...)                                                                                                                                                                                        \
    ll __VA_ARGS__;                                                                                                                                                                                    \
    inp(__VA_ARGS__);
#define STRING(...)                                                                                                                                                                                    \
    string __VA_ARGS__;                                                                                                                                                                                \
    inp(__VA_ARGS__);
#define CHAR(...)                                                                                                                                                                                      \
    char __VA_ARGS__;                                                                                                                                                                                  \
    inp(__VA_ARGS__);
#define VEC(T, A, n)                                                                                                                                                                                   \
    vector<T> A(n);                                                                                                                                                                                    \
    inp(A);
#define VVEC(T, A, n, m)                                                                                                                                                                               \
    vector<vector<T>> A(n, vector<T>(m));                                                                                                                                                              \
    inp(A);

const ll MOD1 = 1000000007;
const ll MOD9 = 998244353;

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 T, class S>
auto clamp(T &a, const S &l, const S &r) {
    return (a > r ? r : a < l ? l : a);
}
template <class T, class S>
inline bool chmax(T &a, const S &b) {
    return (a < b ? a = b, 1 : 0);
}
template <class T, class S>
inline bool chmin(T &a, const S &b) {
    return (a > b ? a = b, 1 : 0);
}
template <class T, class S>
inline bool chclamp(T &a, const S &l, const S &r) {
    auto b = clamp(a, l, r);
    return (a != b ? a = b, 1 : 0);
}

void FLUSH() {
    cout << flush;
}
void print() {
    cout << endl;
}
template <class Head, class... Tail>
void print(Head &&head, Tail &&... tail) {
    cout << head;
    if (sizeof...(Tail)) cout << spa;
    print(forward<Tail>(tail)...);
}
template <typename T>
void print(vector<T> &A) {
    int n = A.size();
    for (int i = 0; i < n; i++) {
        cout << A[i];
        if (i != n - 1) cout << ' ';
    }
    cout << endl;
}
template <typename T>
void print(vector<vector<T>> &A) {
    for (auto &row : A) print(row);
}
template <typename T, typename S>
void print(pair<T, S> &A) {
    cout << A.first << spa << A.second << endl;
}
template <typename T, typename S>
void print(vector<pair<T, S>> &A) {
    for (auto &row : A) print(row);
}
template <typename T, typename S>
void prisep(vector<T> &A, S sep) {
    int n = A.size();
    for (int i = 0; i < n; i++) {
        cout << A[i];
        if (i != n - 1) cout << sep;
    }
    cout << endl;
}
template <typename T, typename S>
void priend(T A, S end) {
    cout << A << end;
}
template <typename T>
void priend(T A) {
    priend(A, spa);
}
template <class... T>
void inp(T &... a) {
    (cin >> ... >> a);
}
template <typename T>
void inp(vector<T> &A) {
    for (auto &a : A) cin >> a;
}
template <typename T>
void inp(vector<vector<T>> &A) {
    for (auto &row : A) inp(row);
}
template <typename T, typename S>
void inp(pair<T, S> &A) {
    inp(A.first, A.second);
}
template <typename T, typename S>
void inp(vector<pair<T, S>> &A) {
    for (auto &row : A) inp(row.first, row.second);
}

template <typename T>
T sum(vector<T> &A) {
    T tot = 0;
    for (auto a : A) tot += a;
    return tot;
}

template <typename T>
vector<T> compression(vector<T> X) {
    sort(all(X));
    X.erase(unique(all(X)), X.end());
    return X;
}

vector<vector<int>> read_edges(int n, int m, bool direct = false, int indexed = 1) {
    vector<vector<int>> edges(n, vector<int>());
    for (int i = 0; i < m; i++) {
        INT(u, v);
        u -= indexed;
        v -= indexed;
        edges[u].push_back(v);
        if (!direct) edges[v].push_back(u);
    }
    return edges;
}
vector<vector<int>> read_tree(int n, int indexed = 1) {
    return read_edges(n, n - 1, false, indexed);
}
template <typename T>
vector<vector<pair<int, T>>> read_wedges(int n, int m, bool direct = false, int indexed = 1) {
    vector<vector<pair<int, T>>> edges(n, vector<pair<int, T>>());
    for (int i = 0; i < m; i++) {
        INT(u, v);
        T w;
        inp(w);
        u -= indexed;
        v -= indexed;
        edges[u].push_back({v, w});
        if (!direct) edges[v].push_back({u, w});
    }
    return edges;
}
template <typename T>
vector<vector<pair<int, T>>> read_wtree(int n, int indexed = 1) {
    return read_wedges<T>(n, n - 1, false, indexed);
}

inline bool yes(bool f = true) {
    cout << (f ? "yes" : "no") << endl;
    return f;
}
inline bool Yes(bool f = true) {
    cout << (f ? "Yes" : "No") << endl;
    return f;
}
inline bool YES(bool f = true) {
    cout << (f ? "YES" : "NO") << endl;
    return f;
}

inline bool no(bool f = true) {
    cout << (!f ? "yes" : "no") << endl;
    return f;
}
inline bool No(bool f = true) {
    cout << (!f ? "Yes" : "No") << endl;
    return f;
}
inline bool NO(bool f = true) {
    cout << (!f ? "YES" : "NO") << endl;
    return f;
}

// start tree/LCA.hpp

struct LCA {
    int n;
    int logn;
    vector<vector<int>> par;
    vector<vector<int>> edges;
    vector<int> depth;
    LCA(int n) : n(n) {
        logn  = 0;
        int x = 1;
        while (x < n) {
            x *= 2;
            logn++;
        }
        par.assign(logn, vector<int>(n, -1));
        edges.resize(n);
        depth.assign(n, -1);
    }

    void read_edges(int indexed = 1) {
        int u, v;
        for (int i = 0; i < n - 1; i++) {
            cin >> u >> v;
            u -= indexed;
            v -= indexed;
            edges[u].push_back(v);
            edges[v].push_back(u);
        }
    }

    void add_edge(int u, int v) {
        edges[u].push_back(v);
        edges[v].push_back(u);
    }

    void build(int root = 0) {
        stack<int> st;
        st.push(root);
        depth[root] = 0;
        while (!st.empty()) {
            int pos = st.top();
            st.pop();
            for (auto npos : edges[pos]) {
                if (depth[npos] == -1) {
                    depth[npos]  = depth[pos] + 1;
                    par[0][npos] = pos;
                    st.push(npos);
                }
            }
        }

        for (int i = 1; i < logn; i++) {
            for (int j = 0; j < n; j++) {
                int p = par[i - 1][j];
                if (p != -1) {
                    par[i][j] = par[i - 1][p];
                }
            }
        }
    }

    int lca(int u, int v) {
        int du = depth[u];
        int dv = depth[v];
        if (du > dv) {
            swap(u, v);
            swap(du, dv);
        }
        int d = dv - du;
        int i = 0;
        while (d > 0) {
            if (d & 1) v = par[i][v];
            d >>= 1;
            i++;
        }

        if (u == v) return u;
        for (int i = logn - 1; i >= 0; i--) {
            int pu = par[i][u];
            int pv = par[i][v];
            if (pu != pv) {
                u = pu;
                v = pv;
            }
        }
        return par[0][u];
    }

    int dist(int u, int v) {
        int p = lca(u, v);
        return depth[u] + depth[v] - 2 * depth[p];
    }

    int jump(int u, int v, int k) {
        if (k == 0) return u;
        int p  = lca(u, v);
        int du = depth[u] - depth[p];
        int dv = depth[v] - depth[p];
        if (du + dv < k) return -1;
        int d;
        if (k <= du) {
            d = k;
        } else {
            u = v;
            d = du + dv - k;
        }

        int i = 0;
        while (d > 0) {
            if (d & 1) u = par[i][u];
            d >>= 1;
            i++;
        }

        return u;
    }
};

// end tree/LCA.hpp
// restart A.cpp

void solve() {
    INT(n, Q);
    LCA G(n);
    G.read_edges();
    G.build();
    vec(ll, siz, n, 1);

    auto dfs = [&](auto &&self, int pos, int bpos) -> void {
        for (auto npos : G.edges[pos]) {
            if (npos == bpos) continue;
            self(self, npos, pos);
            siz[pos] += siz[npos];
        }
    };
    dfs(dfs, 0, -1);
    fori(Q) {
        INT(u, v);
        u--;
        v--;
        ll d = G.dist(u, v);
        if (d & 1) {
            print(0);
            continue;
        }
        d /= 2;
        int a  = G.jump(u, v, d - 1);
        int b  = G.jump(u, v, d);
        int c  = G.jump(u, v, d + 1);
        ll ans = n;
        if (G.depth[a] > G.depth[b])
            ans -= siz[a];
        else
            ans -= n - siz[b];

        if (G.depth[c] > G.depth[b])
            ans -= siz[c];
        else
            ans -= n - siz[b];

        print(ans);
    }
}

int main() {
    cin.tie(0)->sync_with_stdio(0);
    // cout << fixed << setprecision(12);
    int t;
    t = 1;
    // cin >> t;
    while (t--) solve();
    return 0;
}

// end A.cpp
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