Submission #895301

#	Time	Username	Problem	Language	Result	Execution time	Memory
895301		themm1	Spring cleaning (CEOI20_cleaning)	C++17	100 / 100	300 ms	24284 KiB

cleaning

#include <bits/stdc++.h>
using namespace std;
// ordered set whith s.order_of_key(x) method, which returns rank of element x in set s
/*
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace __gnu_pbds;
typedef tree<int, null_type, less_equal<int>, rb_tree_tag, tree_order_statistics_node_update> ordered_set;
*/

// pair printing
template <class T, class U>
ostream& operator<<(ostream& out, const pair<T, U> &par) {out << "(" << par.first << "; " << par.second << ")"; return out;}
// set printing
template <class T>
ostream& operator<<(ostream& out, const set<T> &cont) { out << "{"; for(const auto &x:cont) out << x << ", "; out << "}"; return out; }
// map printing
template <class T, class U>
ostream& operator<<(ostream& out, const map<T, U> &cont) {out << "{"; for(const auto &x:cont) out << x << ", "; out << "}"; return out; }
// unordered_set printing
template <class T>
ostream& operator<<(ostream& out, const unordered_set<T> &cont) {out << "{";for(const auto &x:cont) out << x << ", ";out << "}";return out;}
// unordered_map printing
template <class T, class U>
ostream& operator<<(ostream& out, const unordered_map<T, U> &cont) {out << "{";for(const auto &x:cont) out << x << ", ";out << "}";return out;}
// vector printing
template<class T>
ostream& operator<<(ostream& out, const vector<T> &cont){ out << "[";  for (const auto &x:cont) out << x << ", ";  out << "]"; return out;}

#define print(x) cout << (x) << endl;
#define dmp(x) cerr << #x << " = " << x << endl
#define dmpn(x) cerr << #x << " = " << x << "; "
#define dmpl(x) cerr << "Line " << __LINE__ << ": " << #x << " = " << x << endl

using ll = long long;
using ld = long double;
using pii = pair<int, int>;
using pll = pair<ll, ll>;
#define pb push_back
#define ff first
#define ss second
#define all(x) begin(x), end(x)
#define sz(x) (int)x.size()
#define contains(s,x) ((s).find(x) != (s).end())
const int MOD = 998244353;

struct LazySegtree {
        int N;
        vector<int> sums, flipped;
        LazySegtree(vector<int> &a) {
                N = pow(2, ceil(log2(sz(a))));
                sums.assign(2 * N, 0);
                flipped.assign(2 * N, 0);
                for (int i = 0; i < sz(a); i++) sums[i + N] = a[i];
                for (int i = N - 1; i >= 1; i--) sums[i] = sums[i * 2] + sums[i * 2 + 1];
                // dmp(sums);
                // dmp(flipped);
        }

        int get_sum(int idx, int i, int j) {
                if (flipped[idx]) return (j - i) - sums[idx];
                return sums[idx];
        }

        void push_lazy(int idx, int i, int j) {
                if (flipped[idx]) {
                        flipped[idx * 2] ^= 1;
                        flipped[idx * 2 + 1] ^= 1;
                        flipped[idx] = 0;
                }
        }

        int query(int l, int r, int i, int j, int idx = 1) {
                // aktualny je cely v povodnom
                if (l <= i && j <= r) {
                        return get_sum(idx, i, j);
                // prekryva sa
                } else if ((i <= l && l < j) || (i < r && r <= j)) {
                        push_lazy(idx, i, j);
                        int mid = (i + j) / 2;
                        return query(l, r, i, mid, idx * 2) + query(l, r, mid, j, idx * 2 + 1);
                }
                return 0;
        }

        void lazy_update(int l, int r, int i, int j, int idx = 1) {
                if (l <= i && j <= r) {
                        flipped[idx] ^= 1;
                } else if ((i <= l && l < j) || (i < r && r <= j)) {
                        push_lazy(idx, i, j);
                        int mid = (i + j) / 2;
                        lazy_update(l, r, i, mid, idx * 2);
                        lazy_update(l, r, mid, j, idx * 2 + 1);
                        sums[idx] = get_sum(idx * 2, i, mid) + get_sum(idx * 2 + 1, mid, j);
                }
        }

        void print_row(int l, int r) {
                for (int i = l; i < r; i++) cout << query(i, i + 1, 0, N) << " ";
                cout << endl;
        }
};

int N, Q;
vector<vector<int>> g;
vector<int> intimes, tops, is_evens, parents;

int dfs1(int v, int p) {
        int size = 1, mx = 0, mxi = -1;
        is_evens[v] = (sz(g[v]) == 1) ? 0 : 1;
        parents[v] = p;
        for (int i = 0; i < sz(g[v]); i++) if (g[v][i] != p) {
                int u = g[v][i];
                int usz = dfs1(u, v);
                if (usz > mx) {
                        mx = usz;
                        mxi = i;
                }
                size += usz;
                if (!is_evens[u]) is_evens[v] ^= 1;
        }
        if (mxi != -1) swap(g[v][0], g[v][mxi]);
        return size;
}

int dfs2(int v, int p, int time, int top) {
        intimes[v] = time;
        tops[v] = top;
        for (int i = 0; i < sz(g[v]); i++) if (g[v][i] != p) {
                int u = g[v][i];
                if (i == 0) time = dfs2(u, v, time + 1, top);
                else time = dfs2(u, v, time + 1, u);
        }
        return time;
}

void solve() {
        cin >> N >> Q;
        g.assign(N, {});
        is_evens.assign(N, 0);
        parents.assign(N, -1);
        intimes.assign(N, 0);
        tops.assign(N, 0);
        for (int i = 0; i < N - 1; i++) {
                int u, v;
                cin >> u >> v;
                u--;
                v--;
                g[u].pb(v);
                g[v].pb(u);
        }
        int root = 0, leaves = 0;
        for (int i = 0; i < N; i++) if (sz(g[i]) == 1) leaves++;
        dfs1(root, -1);
        dfs2(root, -1, 0, root);

        vector<int> base(N, 0);
        for (int i = 0; i < N; i++) base[intimes[i]] = is_evens[i];
        LazySegtree st(base);
        // st.print_row(0, N);
        while (Q--) {
                int K;
                cin >> K;
                bool even = ((leaves + K) % 2 == 0);
                map<int, int> m;
                for (int i = 0; i < K; i++) {
                        int v;
                        cin >> v;
                        v--;
                        m[v]++;
                }
                map<pii, int> updates;
                int x = 0;
                for (pii kv : m) {
                        int v = kv.ff;
                        if (sz(g[v]) == 1) even ^= 1;
                        if ((sz(g[v]) == 1 && kv.ss % 2 == 1) || (sz(g[v]) != 1 && kv.ss % 2 == 0)) continue;
                        while (v != -1) {
                                pii pr = { intimes[tops[v]], intimes[v] + 1 };
                                updates[pr]++;
                                v = parents[tops[v]];
                                x++;
                        }
                }
                for (auto kv : updates) if (kv.ss % 2 == 1) st.lazy_update(kv.ff.ff, kv.ff.ss, 0, st.N);
                if (!even) cout << -1 << endl;
                else {
                        int even_cnt = st.query(0, N, 0, st.N);
                        int ans = N + K - 2 + even_cnt;
                        cout << ans << endl;
                }
                for (auto kv : updates) if (kv.ss % 2 == 1) st.lazy_update(kv.ff.ff, kv.ff.ss, 0, st.N);
        }
}

int32_t main() {
        ios::sync_with_stdio(false);
        cin.tie(0);
        cout.tie(0);

        // clock_t start = clock();
        int t = 1;
        // cin >> t;
        while (t--) {
                solve();
        }
        // cout << (clock() - start) / 1000 << " ms" << endl;
}

• Subtask 1: 0 / 0
• Subtask 2: 9 / 9
• Subtask 3: 9 / 9
• Subtask 4: 16 / 16
• Subtask 5: 19 / 19
• Subtask 6: 17 / 17
• Subtask 7: 30 / 30