Submission #1365820

#TimeUsernameProblemLanguageResultExecution timeMemory
1365820vlad7654Birthday gift (IZhO18_treearray)C++20
56 / 100
4094 ms39436 KiB
#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

const int MAXN = 200005;
const int LOGN = 19;

vector<int> adj[MAXN];
int tin[MAXN], tout[MAXN], timer;
int up[MAXN][LOGN];
int a[MAXN];
int n, m, q;

void dfs(int v, int p) {
    tin[v] = ++timer;
    up[v][0] = p;
    for (int i = 1; i < LOGN; i++)
        up[v][i] = up[up[v][i - 1]][i - 1];
    for (int u : adj[v]) {
        if (u != p) dfs(u, v);
    }
    tout[v] = timer;
}

bool is_ancestor(int u, int v) {
    return tin[u] <= tin[v] && tout[u] >= tout[v];
}

int get_lca(int u, int v) {
    if (u == 0) return v;
    if (v == 0) return u;
    if (is_ancestor(u, v)) return u;
    if (is_ancestor(v, u)) return v;
    for (int i = LOGN - 1; i >= 0; i--) {
        if (!is_ancestor(up[u][i], v))
            u = up[u][i];
    }
    return up[u][0];
}

struct Node {
    int lca_val;
    int min_t, max_t;
} tree[4 * MAXN];

Node merge(Node l, Node r) {
    if (l.lca_val == 0) return r;
    if (r.lca_val == 0) return l;
    return {get_lca(l.lca_val, r.lca_val), min(l.min_t, r.min_t), max(l.max_t, r.max_t)};
}

void build(int node, int start, int end) {
    if (start == end) {
        tree[node] = {a[start], tin[a[start]], tin[a[start]]};
        return;
    }
    int mid = (start + end) / 2;
    build(2 * node, start, mid);
    build(2 * node + 1, mid + 1, end);
    tree[node] = merge(tree[2 * node], tree[2 * node + 1]);
}

void update(int node, int start, int end, int pos, int val) {
    if (start == end) {
        tree[node] = {val, tin[val], tin[val]};
        return;
    }
    int mid = (start + end) / 2;
    if (pos <= mid) update(2 * node, start, mid, pos, val);
    else update(2 * node + 1, mid + 1, end, pos, val);
    tree[node] = merge(tree[2 * node], tree[2 * node + 1]);
}

Node range_query(int node, int start, int end, int l, int r) {
    if (r < start || end < l) return {0, (int)2e9, -1};
    if (l <= start && end <= r) return tree[node];
    int mid = (start + end) / 2;
    return merge(range_query(2 * node, start, mid, l, r), range_query(2 * node + 1, mid + 1, end, l, r));
}

int find_first_not(int node, int start, int end, int L, int R, int v) {
    if (start > R || end < L || (tin[v] <= tree[node].min_t && tree[node].max_t <= tout[v]))
        return -1;
    if (start == end) return start;
    int mid = (start + end) / 2;
    int res = find_first_not(2 * node, start, mid, L, R, v);
    if (res == -1) res = find_first_not(2 * node + 1, mid + 1, end, L, R, v);
    return res;
}

void solve() {
    int L, R, V;
    cin >> L >> R >> V;
    int cur = L;
    while (cur <= R) {
        int next_not = find_first_not(1, 1, m, cur, R, V);
        int segment_end = (next_not == -1) ? R : next_not - 1;

        if (segment_end >= cur) {
            Node res = range_query(1, 1, m, cur, segment_end);
            if (res.lca_val == V) {
                cout << cur << " " << segment_end << "\n";
                return;
            }
        }
        if (next_not == -1) break;
        cur = next_not + 1;
    }
    cout << "-1 -1\n";
}

int main() {
    ios::sync_with_stdio(false); cin.tie(NULL);
    cin >> n >> m >> q;
    for (int i = 0, u, v; i < n - 1; i++) {
        cin >> u >> v;
        adj[u].push_back(v); adj[v].push_back(u);
    }
    dfs(1, 1);
    for (int i = 1; i <= m; i++) cin >> a[i];
    build(1, 1, m);
    while (q--) {
        int t; cin >> t;
        if (t == 1) {
            int p, v; cin >> p >> v;
            a[p] = v;
            update(1, 1, m, p, v);
        } else solve();
    }
    return 0;
}
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