結果
問題 | No.2337 Equidistant |
ユーザー | Kude |
提出日時 | 2023-06-02 22:21:16 |
言語 | C++17 (gcc 12.3.0 + boost 1.83.0) |
結果 |
AC
|
実行時間 | 289 ms / 4,000 ms |
コード長 | 4,322 bytes |
コンパイル時間 | 2,955 ms |
コンパイル使用メモリ | 234,832 KB |
実行使用メモリ | 35,304 KB |
最終ジャッジ日時 | 2024-06-08 23:43:07 |
合計ジャッジ時間 | 9,705 ms |
ジャッジサーバーID (参考情報) |
judge1 / judge3 |
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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 | 2 ms
5,248 KB |
testcase_01 | AC | 3 ms
5,376 KB |
testcase_02 | AC | 3 ms
5,376 KB |
testcase_03 | AC | 3 ms
5,376 KB |
testcase_04 | AC | 3 ms
5,376 KB |
testcase_05 | AC | 3 ms
5,376 KB |
testcase_06 | AC | 5 ms
5,376 KB |
testcase_07 | AC | 5 ms
5,376 KB |
testcase_08 | AC | 5 ms
5,376 KB |
testcase_09 | AC | 5 ms
5,376 KB |
testcase_10 | AC | 4 ms
5,376 KB |
testcase_11 | AC | 257 ms
19,840 KB |
testcase_12 | AC | 247 ms
19,840 KB |
testcase_13 | AC | 244 ms
19,840 KB |
testcase_14 | AC | 238 ms
19,884 KB |
testcase_15 | AC | 263 ms
19,876 KB |
testcase_16 | AC | 261 ms
19,840 KB |
testcase_17 | AC | 262 ms
19,764 KB |
testcase_18 | AC | 243 ms
19,824 KB |
testcase_19 | AC | 241 ms
19,840 KB |
testcase_20 | AC | 247 ms
19,840 KB |
testcase_21 | AC | 228 ms
35,304 KB |
testcase_22 | AC | 162 ms
20,408 KB |
testcase_23 | AC | 184 ms
20,540 KB |
testcase_24 | AC | 265 ms
30,080 KB |
testcase_25 | AC | 213 ms
20,520 KB |
testcase_26 | AC | 289 ms
29,952 KB |
testcase_27 | AC | 215 ms
20,608 KB |
testcase_28 | AC | 226 ms
20,404 KB |
ソースコード
#include<bits/stdc++.h> namespace { #pragma GCC diagnostic ignored "-Wunused-function" #include<atcoder/all> #pragma GCC diagnostic warning "-Wunused-function" using namespace std; using namespace atcoder; #define rep(i,n) for(int i = 0; i < (int)(n); i++) #define rrep(i,n) for(int i = (int)(n) - 1; i >= 0; i--) #define all(x) begin(x), end(x) #define rall(x) rbegin(x), rend(x) template<class T> bool chmax(T& a, const T& b) { if (a < b) { a = b; return true; } else return false; } template<class T> bool chmin(T& a, const T& b) { if (b < a) { a = b; return true; } else return false; } 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 { const vector<vector<int>>& to; int root, n; vector<int> sz, parent, depth, idx, ridx, head, inv; HLD(const vector<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, -1, 0); int nxt = 0; assign_idx(root, root, nxt); } void init_tree_data(int u, int p, int d) { parent[u] = p; depth[u] = d; int s = 1; for (int v: to[u]) if (v != p) { 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; idx[u] = nxt; inv[nxt] = u; nxt++; int heaviest = -1; int mxweight = 0; for (int v: to[u]) if (v != p) { if (sz[v] > mxweight) { heaviest = v; mxweight = sz[v]; } } if (heaviest != -1) { assign_idx(heaviest, h, nxt, u); for (int v: to[u]) if (v != p && v != heaviest) { 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 reference to tuple of (path fragments from x upto lca (excluding lca), those from y, lca) // storage of retval is reused to avoid creating short vectors on each query tuple<vector<pair<int, int>>, vector<pair<int, int>>, int> paths_res; auto& paths(int x, int y) { auto& [x_paths, y_paths, lca] = paths_res; x_paths.clear(); y_paths.clear(); while (head[x] != head[y]) { int hx = head[x], hy = head[y]; if (depth[hx] > depth[hy]) { x_paths.emplace_back(x, hx); x = parent[hx]; } else { y_paths.emplace_back(y, hy); y = parent[hy]; } } if (depth[x] > depth[y]) { x_paths.emplace_back(x, inv[idx[y] + 1]); x = y; } else if (depth[x] < depth[y]) { y_paths.emplace_back(y, inv[idx[x] + 1]); y = x; } lca = x; return paths_res; } int dist(int u, int v) { int w = lca(u, v); return depth[u] + depth[v] - 2 * depth[w]; } template <class F> int max_ancestor(int v, F f) { if (!f(v)) return -1; int hv = head[v]; int p = parent[hv]; while (p != -1 && f(p)) { v = p; hv = head[v]; p = parent[hv]; } int il = idx[hv] - 1, ir = idx[v]; while (ir - il > 1) { int ic = (il + ir) / 2; (f(inv[ic]) ? ir : il) = ic; } return inv[ir]; } int ascend(int v, int k) { assert(depth[v] >= k); int td = depth[v] - k; int hv = head[v]; while (depth[hv] > td) { v = parent[hv]; hv = head[v]; } int rest = depth[v] - td; return inv[idx[v] - rest]; } }; } int main() { ios::sync_with_stdio(false); cin.tie(0); int n, q; cin >> n >> q; VVI to(n); rep(_ , n - 1) { int u, v; cin >> u >> v; u--, v--; to[u].emplace_back(v); to[v].emplace_back(u); } HLD hld(to); rep(_, q) { int s, t; cin >> s >> t; s--, t--; if (hld.depth[s] < hld.depth[t]) swap(s, t); int d = hld.dist(s, t); if (d % 2) { cout << 0 << '\n'; continue; } int c = hld.ascend(s, d / 2); int ans = n; for(int v : {s, t}) { int l = hld.lca(v, c); if (l == c) { int x = hld.ascend(v, d / 2 - 1); ans -= hld.sz[x]; } else { ans -= n - hld.sz[c]; } } cout << ans << '\n'; } }