151 lines
3.1 KiB
C++
151 lines
3.1 KiB
C++
/* Problem URL: https://codeforces.com/problemset/problem/2018/C */
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#include <bits/stdc++.h>
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using namespace std;
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#define V vector
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#define rmin(a, b) a = min(a, b)
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#define rmax(a, b) a = max(a, b)
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#define rep(i, lim) for (int i = 0; i < (lim); i++)
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#define nrep(i, s, lim) for (int i = s; i < (lim); i++)
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#define repv(i, v) for (auto &i : (v))
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#define fillv(v) for (auto &itr_ : (v)) { cin >> itr_; }
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#define sortv(v) sort(v.begin(), v.end())
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#define all(v) (v).begin(), (v).end()
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using vi = vector<int>;
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using vvi = vector<vi>;
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using vvvi = vector<vvi>;
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using vvvvi = vector<vvvi>;
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using ll = long long;
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using vl = vector<ll>;
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using vvl = vector<vl>;
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using vvvl = vector<vvl>;
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using vvvvl = vector<vvvl>;
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template<class v>
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auto operator<<(ostream &os, const vector<v> &vec)->ostream& {
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os << vec[0];
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for (size_t i = 1; i < vec.size(); i++) {
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os << ' ' << vec[i];
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}
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os << '\n';
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return os;
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}
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template<class v>
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auto operator>>(istream &is, vector<v> &vec)->istream& {
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for (auto &i : vec) {
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is >> i;
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}
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return is;
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}
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template<class v>
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auto operator<<(ostream &os, const vector<vector<v>> &vec)->ostream& {
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for (auto &i : vec) {
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os << i[0];
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for (size_t j = 1; j < i.size(); j++) {
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os << ' ' << i[j];
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}
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os << '\n';
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}
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return os;
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}
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template<class v>
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auto operator>>(istream &is, vector<vector<v>> &vec)->istream& {
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for (auto &i : vec) {
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for (auto &j : i) {
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is >> j;
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}
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}
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return is;
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}
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int main()
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{
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ios::sync_with_stdio(false);
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cin.tie(nullptr);
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int t;
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cin >> t;
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while (t--) {
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int n;
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cin >> n;
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vvi graph(n);
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rep(i, n - 1) {
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int a, b;
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cin >> a >> b;
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a--, b--;
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graph[a].push_back(b);
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graph[b].push_back(a);
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}
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if (n > 1) {
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n = 1 << (32 - __builtin_clz(n));
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}
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vi seg(n * 2);
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function<void(int, int, int, int, int)> update = [&](int i, int l, int r, int tl, int tr) {
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if (l > tr || r < tl) {
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return;
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}
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if (l >= tl && r <= tr) {
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seg[i]++;
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return;
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}
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int mid = (l + r) / 2;
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update(i * 2, l, mid, tl, tr );
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update(i * 2 + 1, mid + 1, r, tl, tr);
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};
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auto get = [&](int i) {
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int ans = 0;
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for (i = (i + n); i > 0; i /= 2) {
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ans += seg[i];
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}
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return ans;
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};
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function<int(int, int, int)> dfs = [&](int i, int p, int d) {
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int ans = d;
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repv(j, graph[i]) {
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if (j == p) {
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continue;
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}
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rmax(ans, dfs(j, i, d + 1));
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}
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update(1, 0, n - 1, 0, d - 1);
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update(1, 0, n - 1, ans + 1, n - 1);
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return ans;
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};
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dfs(0, 0, 0);
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int ans = INT32_MAX >> 1;
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rep(i, n) {
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rmin(ans, get(i));
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}
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cout << ans << '\n';
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}
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}
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