Submission #1240898

#	Time	Username	Problem	Language	Result	Execution time	Memory
1240898		_callmelucian	Birthday gift (IZhO18_treearray)	C++17	100 / 100	410 ms	69372 KiB

treearray

#include <bits/stdc++.h>
using namespace std;

using ll = long long;
using ld = long double;
using pl = pair<ll,ll>;
using pii = pair<int,int>;
using tpl = tuple<int,int,int>;

#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())

const int mn = 2e5 + 5;
int node[mn], sz[mn], par[mn], chain[mn], depth[mn];
set<int> appear[mn], itself[mn];
vector<int> adj[mn];

int szDfs (int u, int p) {
    sz[u] = 1;
    for (int v : adj[u])
        if (v != p) sz[u] += szDfs(v, u);
    return sz[u];
}

void dfs (int u, int p, int d, bool toP) {
    if (u == 1) szDfs(u, p);
    par[u] = p, chain[u] = (toP ? chain[p] : u), depth[u] = d;
    sort(all(adj[u]), [&] (int a, int b) { return sz[a] > sz[b]; });

    bool heavy = 1;
    for (int v : adj[u])
        if (v != p) dfs(v, u, d + 1, heavy), heavy = 0;
}

int lca (int a, int b) {
    while (chain[a] != chain[b]) {
        int ap = par[chain[a]], bp = par[chain[b]];
        if (depth[ap] == depth[bp]) a = ap, b = bp;
        else if (depth[ap] > depth[bp]) a = ap;
        else if (depth[bp] > depth[ap]) b = bp;
    }
    return (depth[a] < depth[b] ? a : b);
}

void addNode (int i) { appear[lca(node[i - 1], node[i])].insert(i); }
void removeNode (int i) { appear[lca(node[i - 1], node[i])].erase(i); }

int main()
{
    ios::sync_with_stdio(0);
    cin.tie(0);

    int n, m, q; cin >> n >> m >> q;
    for (int i = 1; i < n; i++) {
        int a, b; cin >> a >> b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    dfs(1, 0, 1, 0);

    for (int i = 1; i <= m; i++) {
        cin >> node[i];
        itself[node[i]].insert(i);
    }
    for (int i = 2; i <= m; i++) addNode(i);

    while (q--) {
        int type; cin >> type;
        if (type == 1) {
            int pos, v; cin >> pos >> v;
            removeNode(pos), removeNode(pos + 1), itself[node[pos]].erase(pos);
            node[pos] = v;
            addNode(pos), addNode(pos + 1), itself[node[pos]].insert(pos);
        }
        else {
            int l, r, v; cin >> l >> r >> v;
            auto it = appear[v].upper_bound(l);
            if (it != appear[v].end() && *it <= r)
                cout << *it - 1 << " " << *it << "\n";
            else {
                it = itself[v].lower_bound(l);
                if (it != itself[v].end() && *it <= r) cout << *it << " " << *it << "\n";
                else cout << "-1 -1\n";
            }
        }
    }

    return 0;
}

• Subtask 1: 12 / 12
• Subtask 2: 18 / 18
• Subtask 3: 26 / 26
• Subtask 4: 44 / 44