Submission #1175397

#	Time	Username	Problem	Language	Result	Execution time	Memory
1175397		qrn	Birthday gift (IZhO18_treearray)	C++20	0 / 100	8 ms	19264 KiB

treearray

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

#define SPEED                     \
    ios_base::sync_with_stdio(0); \
    cin.tie(NULL);                \
    cout.tie(NULL);

#define pb push_back
#define ins insert
#define fi first
#define se second

#define endl "\n"
#define ALL(x) x.begin(), x.end()
#define sz(x) x.size()
#define intt long long

const intt mod = 1e9 + 7;
const intt base = 31;
const intt inf = 1e18;
const intt mxN = 2e5 + 5;
const intt L = 21;

set<intt> pos[mxN], pos2[mxN];
intt up[L][mxN], in[mxN], out[mxN], a[mxN], timer, n, k, q;
vector<vector<intt>> graph;

void dfs(intt node, intt parent) {
    in[node] = timer++;
    up[0][node] = parent;
    for(intt i = 1; i <= L; i++) {
        up[i][node] = up[i-1][up[i-1][node]];
    }
    
    for(auto u : graph[node]) {
        if(u != parent) {
            dfs(u, node);
        }
    }
    out[node] = timer++;
}

bool isata(intt a, intt b) {
    return in[a] <= in[b] && out[a] >= out[b];
}

intt lca(intt a, intt b) {
    if(isata(a, b)) return a;
    if(isata(b, a)) return b;
    
    for(intt i = L - 1; i >= 0; i--) {
        if(!isata(up[i][a], b)) {
            a = up[i][a];
        }
    }
    return up[0][a];
}

void solve() {
    cin >> n >> k >> q;
    graph.assign(n + 1, vector<intt>());
    for(intt i = 1; i <= n - 1; i++) {
        intt a, b;
        cin >> a >> b;
        graph[a].pb(b);
        graph[b].pb(a);
    }
    dfs(1, 1);
    for(intt i = 1; i <= k; i++) {
        cin >> a[i];
        pos2[a[i]].insert(i);
    }
    vector<intt> ls(n + 5, 0);
    for(intt i = 1; i <= k - 1; i++) {
        intt l = lca(a[i], a[i + 1]);
        pos[l].insert(i);
        ls[i] = l;
    }

    while(q--) {
        intt t;
        cin >> t;
        if(t == 1) {
            intt idx, v;
            cin >> idx >> v;
            pos2[a[idx]].erase(idx);
            a[idx] = v;
            pos2[a[idx]].insert(idx);
            
            if (idx != 1) {
                intt pl = ls[idx - 1], nl = lca(a[idx - 1], a[idx]);
                pos[pl].erase(idx - 1);
                ls[idx - 1] = nl;
                pos[nl].insert(idx - 1);
            }
            if (idx != k) {
                intt pl = ls[idx], nl = lca(a[idx], a[idx + 1]);
                pos[pl].erase(idx);
                ls[idx] = nl;
                pos[nl].insert(idx);
            }
        } else {
            intt l, r, v;
            cin >> l >> r >> v;
            auto it = pos[v].lower_bound(l);
            if(it != pos[v].end()) {
                intt indl = *it;
                if(indl < r) {
                    cout << indl << " " << indl + 1 <<endl;
                    continue;
                }
            } else {
                it = pos2[v].lower_bound(l);
                if(it == pos2[v].end()) {
                    cout << -1 << " " << -1 << endl;
                } else{
                    cout << *it << " " << *it << endl;
                }
            }
        }
    }
}

signed main() {
    SPEED;
    intt tst = 1;
    // cin >> tst;
    while (tst--) {
        solve();
    }
}

Compilation message (stderr)

treearray.cpp: In function 'void dfs(long long int, long long int)':
treearray.cpp:33:21: warning: iteration 20 invokes undefined behavior [-Waggressive-loop-optimizations]
   33 |         up[i][node] = up[i-1][up[i-1][node]];
      |         ~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
treearray.cpp:32:23: note: within this loop
   32 |     for(intt i = 1; i <= L; i++) {
      |                     ~~^~~~

• Subtask 1: 0 / 12
• Subtask 2: 0 / 18
• Subtask 3: 0 / 26
• Subtask 4: 0 / 44