結果

問題 No.1326 ふたりのDominator
ユーザー Kude
提出日時 2020-12-25 04:03:22
言語 C++17
(gcc 13.3.0 + boost 1.87.0)
結果
AC  
実行時間 134 ms / 2,000 ms
コード長 9,567 bytes
コンパイル時間 2,464 ms
コンパイル使用メモリ 218,116 KB
最終ジャッジ日時 2025-01-17 07:03:14
ジャッジサーバーID
（参考情報） 		judge2 / judge5
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 * 1
other AC * 24
権限があれば一括ダウンロードができます
コンパイルメッセージ
In member function ‘void HLD::assign_idx(int, int, int&, int)’,
    inlined from ‘void HLD::assign_idx(int, int, int&, int)’ at main.cpp:200:23,
    inlined from ‘void HLD::assign_idx(int, int, int&, int)’ at main.cpp:200:23,
    inlined from ‘void HLD::assign_idx(int, int, int&, int)’ at main.cpp:200:23:
main.cpp:197:19: warning: ‘mi’ may be used uninitialized [-Wmaybe-uninitialized]
  197 |         assign_idx(mi, h, nxt, u);
      |         ~~~~~~~~~~^~~~~~~~~~~~~~~
main.cpp: In member function ‘void HLD::assign_idx(int, int, int&, int)’:
main.cpp:189:13: note: ‘mi’ was declared here
  189 |         int mi;
      |             ^~
In member function ‘void HLD::assign_idx(int, int, int&, int)’,
    inlined from ‘void HLD::assign_idx(int, int, int&, int)’ at main.cpp:200:23,
    inlined from ‘void HLD::assign_idx(int, int, int&, int)’ at main.cpp:200:23:
main.cpp:197:19: warning: ‘mi’ may be used uninitialized [-Wmaybe-uninitialized]
  197 |         assign_idx(mi, h, nxt, u);
      |         ~~~~~~~~~~^~~~~~~~~~~~~~~
main.cpp: In member function ‘void HLD::assign_idx(int, int, int&, int)’:
main.cpp:189:13: note: ‘mi’ was declared here
  189 |         int mi;
      |             ^~
In member function ‘void HLD::assign_idx(int, int, int&, int)’,
    inlined from ‘void HLD::assign_idx(int, int, int&, int)’ at main.cpp:197:19,
    inlined from ‘void HLD::assign_idx(int, int, int&, int)’ at main.cpp:200:23:
main.cpp:197:19: warning: ‘mi’ may be used uninitialized [-Wmaybe-uninitialized]
  197 |         assign_idx(mi, h, nxt, u);
      |         ~~~~~~~~~~^~~~~~~~~~~~~~~
main.cpp: In member function ‘void HLD::assign_idx(int, int, int&, int)’:
main.cpp:189:13: note: ‘mi’ was declared here
  189 |         int mi;
      |             ^~
In member function ‘void HLD::assign_idx(int, int, int&, int)’,
    inlined from ‘void HLD::assign_idx(int, int, int&, int)’ at main.cpp:200:23,
    inlined f

ソースコード

diff # 

#include<bits/stdc++.h>

#include <cassert>
#include <vector>


#include <cassert>
#include <numeric>
#include <type_traits>

namespace atcoder {

namespace internal {

#ifndef _MSC_VER
template <class T>
using is_signed_int128 =
    typename std::conditional<std::is_same<T, __int128_t>::value ||
                                  std::is_same<T, __int128>::value,
                              std::true_type,
                              std::false_type>::type;

template <class T>
using is_unsigned_int128 =
    typename std::conditional<std::is_same<T, __uint128_t>::value ||
                                  std::is_same<T, unsigned __int128>::value,
                              std::true_type,
                              std::false_type>::type;

template <class T>
using make_unsigned_int128 =
    typename std::conditional<std::is_same<T, __int128_t>::value,
                              __uint128_t,
                              unsigned __int128>;

template <class T>
using is_integral = typename std::conditional<std::is_integral<T>::value ||
                                                  is_signed_int128<T>::value ||
                                                  is_unsigned_int128<T>::value,
                                              std::true_type,
                                              std::false_type>::type;

template <class T>
using is_signed_int = typename std::conditional<(is_integral<T>::value &&
                                                 std::is_signed<T>::value) ||
                                                    is_signed_int128<T>::value,
                                                std::true_type,
                                                std::false_type>::type;

template <class T>
using is_unsigned_int =
    typename std::conditional<(is_integral<T>::value &&
                               std::is_unsigned<T>::value) ||
                                  is_unsigned_int128<T>::value,
                              std::true_type,
                              std::false_type>::type;

template <class T>
using to_unsigned = typename std::conditional<
    is_signed_int128<T>::value,
    make_unsigned_int128<T>,
    typename std::conditional<std::is_signed<T>::value,
                              std::make_unsigned<T>,
                              std::common_type<T>>::type>::type;

#else

template <class T> using is_integral = typename std::is_integral<T>;

template <class T>
using is_signed_int =
    typename std::conditional<is_integral<T>::value && std::is_signed<T>::value,
                              std::true_type,
                              std::false_type>::type;

template <class T>
using is_unsigned_int =
    typename std::conditional<is_integral<T>::value &&
                                  std::is_unsigned<T>::value,
                              std::true_type,
                              std::false_type>::type;

template <class T>
using to_unsigned = typename std::conditional<is_signed_int<T>::value,
                                              std::make_unsigned<T>,
                                              std::common_type<T>>::type;

#endif

template <class T>
using is_signed_int_t = std::enable_if_t<is_signed_int<T>::value>;

template <class T>
using is_unsigned_int_t = std::enable_if_t<is_unsigned_int<T>::value>;

template <class T> using to_unsigned_t = typename to_unsigned<T>::type;

}  // namespace internal

}  // namespace atcoder


namespace atcoder {

template <class T> struct fenwick_tree {
    using U = internal::to_unsigned_t<T>;

  public:
    fenwick_tree() : _n(0) {}
    fenwick_tree(int n) : _n(n), data(n) {}

    void add(int p, T x) {
        assert(0 <= p && p < _n);
        p++;
        while (p <= _n) {
            data[p - 1] += U(x);
            p += p & -p;
        }
    }

    T sum(int l, int r) {
        assert(0 <= l && l <= r && r <= _n);
        return sum(r) - sum(l);
    }

  private:
    int _n;
    std::vector<U> data;

    U sum(int r) {
        U s = 0;
        while (r > 0) {
            s += data[r - 1];
            r -= r & -r;
        }
        return s;
    }
};

}  // namespace atcoder

using namespace std;
using namespace atcoder;
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define rrep(i,n) for(int i = (n)-1; i >= 0; --i)
#define chmax(a, b) a = max(a, b)
#define chmin(a, b) a = min(a, b)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
using ll = long long;
using P = pair<int,int>;
using VI = vector<int>;
using VVI = vector<VI>;
using VL = vector<ll>;
using VVL = vector<VL>;

struct HLD {
    std::vector<std::vector<int>> &to;
    int root, n;
    std::vector<int> sz, parent, depth, idx, ridx, head, inv;
    HLD(std::vector<std::vector<int>>& to, int root=0):
        to(to), root(root), n(to.size()),
        sz(n), parent(n), depth(n), idx(n), ridx(n), head(n), inv(n)
    {
        init_tree_data(root);
        int x = 0;
        assign_idx(root, root, x);
    }
    void init_tree_data(int u, int p=-1, int d=0) {
        parent[u] = p;
        depth[u] = d;
        int s = 1;
        for(int v: to[u]) {
            if (v == p) continue;
            init_tree_data(v, u, d+1);
            s += sz[v];
        }
        sz[u] = s;
    }
    void assign_idx(int u, int h, int &nxt, int p=-1) {
        head[u] = h;
        inv[nxt] = u;
        idx[u] = nxt++;
        if (sz[u] == 1) {
            ridx[u] = nxt;
            return;
        }
        int mxsize = 0;
        int mi;
        for(int v: to[u]) {
            if (v == p) continue;
            if (sz[v] > mxsize) {
                mxsize = sz[v];
                mi = v;
            }
        }
        assign_idx(mi, h, nxt, u);
        for(int v: to[u]) {
            if (v == p || v == mi) continue;
            assign_idx(v, v, nxt, u);
        }
        ridx[u] = nxt;
    }

    int lca(int u, int v) {
        while(head[u] != head[v]) {
            if (depth[head[u]] > depth[head[v]]) u = parent[head[u]];
            else v = parent[head[v]];
        }
        return (depth[u] < depth[v] ? u : v);
    }
    // returns (paths upto lca from x (excluding lca), those from y, lca)
    std::tuple<std::vector<std::pair<int, int>>, std::vector<std::pair<int, int>>, int> paths(int x, int y) {
        std::tuple<std::vector<std::pair<int, int>>, std::vector<std::pair<int, int>>, int> ret;
        std::vector<std::pair<int, int>>& x_paths = get<0>(ret);
        std::vector<std::pair<int, int>>& y_paths = get<1>(ret);
        int& lca = get<2>(ret);
        while(head[x] != head[y]) {
            int xhead = head[x], yhead = head[y];
            if (depth[xhead] > depth[yhead]) {
                x_paths.emplace_back(x, xhead);
                x = parent[xhead];
            } else {
                y_paths.emplace_back(y, yhead);
                y = parent[yhead];
            }
        }
        if (depth[x] > depth[y]) {
            int ychild = inv[idx[y] + 1];
            x_paths.emplace_back(x, ychild);
            x = y;
        } else if (depth[x] < depth[y]) {
            int xchild = inv[idx[x] + 1];
            y_paths.emplace_back(y, xchild);
            y = x;
        }
        lca = x;
        return ret;
    }
};

std::tuple<
    std::vector<std::vector<int>>,
    std::vector<int>,
    std::vector<int>> lowlink(std::vector<std::vector<int>>& to, int root=0) {
    // returns a tuple of (spanning_tree (directed), ord, low)
    std::tuple<
        std::vector<std::vector<int>>,
        std::vector<int>,
        std::vector<int>> res;
    int n = to.size();
    auto& tree = std::get<0>(res);
    auto& ord = std::get<1>(res);
    auto& low = std::get<2>(res);
    tree.resize(n);
    ord.resize(n, -1);
    low.resize(n);
    int nxt_ord = 0;
    auto dfs = [&](auto&& self, int u, int parent=-1)->void {
        low[u] = ord[u] = nxt_ord++;
        for(int v: to[u]) {
            if (v == parent) continue;
            if (ord[v] == -1) {
                tree[u].push_back(v);
                self(self, v, u);
                if (low[v] < low[u]) low[u] = low[v];
            } else {
                if (ord[v] < low[u]) low[u] = ord[v];
            }
        }
    };
    dfs(dfs, root);
    return res;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    int n, m;
    cin >> n >> m;
    VVI graph(n);
    rep(i, m) {
        int u, v;
        cin >> u >> v;
        --u, --v;
        graph[u].push_back(v);
        graph[v].push_back(u);
    }
    auto [tree, ord, low] = lowlink(graph);
    HLD d(tree);
    fenwick_tree<int> fw(n);
    for(int i = 1; i < n; i++) {
        int p = d.parent[i];
        if (p == 0 && tree[p].size() >= 2 || p != 0 && low[i] >= ord[p]) fw.add(d.idx[i], 1);
    }
    int q;
    cin >> q;
    while(q--) {
        int x, y;
        cin >> x >> y;
        x--, y--;
        if (x == y) {
            cout << 0 << '\n';
            continue;
        }
        if (d.depth[x] > d.depth[y]) swap(x, y);
        auto [xpaths, ypaths, lca] = d.paths(x, y);
        int ans = 0;
        bool x_added = false, y_added = false;
        for(auto [s, t]: xpaths) {
            int si = d.idx[s], ti = d.idx[t];
            ans += fw.sum(ti, si + 1);
            x_added = fw.sum(ti, ti + 1) == 1;
        }
        for(auto [s, t]: ypaths) {
            int si = d.idx[s], ti = d.idx[t];
            ans += fw.sum(ti, si + 1);
            y_added = fw.sum(ti, ti + 1) == 1;
        }
        if ((x == lca || x_added) && y_added) ans -= 1;
        cout << ans << '\n';
    }
}
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