Submission #683278

#	Time	Username	Problem	Language	Result	Execution time	Memory
683278		Dima_Borchuk	Birthday gift (IZhO18_treearray)	C++17	0 / 100	4 ms	7380 KiB

treearray

#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define sz(x) int32_t(x.size())
#define pii pair<int,int>
#include<bits/stdc++.h>
#define ld long double
#define ll long long
#define _ << ' ' <<
//#define int ll

using namespace std;
using namespace __gnu_pbds;

const int p = 1009;
const int L = 20;
const int N = (int)3e5 + 5;
const int INF = (int)2e18 + 6;
const int mod = (int)998244353;

mt19937 gen(chrono::system_clock::now().time_since_epoch().count());

template <typename T>
using ordered_set = tree < T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update >;

int a[N], up[N][20], tin[N], tout[N];

vector < int > g[N];

int timer = 0;

void dfs(int v, int anc) {
    tin[v] = ++timer;
    up[v][0] = anc;
    for (int i = 1; i < 20; i++) {
        up[v][i] = up[up[v][i - 1]][i - 1];
    }

    for (auto to : g[v]) {
        if (to == anc) continue;
        dfs(to, v);
    }

    tout[v] = ++timer;
}

bool upper(int a, int b) {
    return (tin[a] <= tin[b] && tout[a] >= tout[b]);
}

int lca(int a, int b) {
    if (upper(a, b)) return a;
    if (upper(b, a)) return b;
    for (int i = 19; i >= 0; i--) {
        if (up[a][i] && !upper(up[a][i], b)) {
            a = up[a][i];
        }
    }
    return up[a][0];
}

int32_t main() {
    #ifdef LOCAL
        freopen("input.txt", "r", stdin);
        freopen("output.txt", "w", stdout);
    #endif // LOCAL

    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    int n, m, q;
    cin >> n >> m >> q;
    for (int i = 1; i < n; i++) {
        int u, v;
        cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    for (int i = 1; i <= m; i++) {
        cin >> a[i];
    }

    dfs(1, 0);

    while (q--) {
        int type;
        cin >> type;
        if (type == 2) {
            int l, r, v;
            cin >> l >> r >> v;
            pii ans = { -1, -1 };
            int mn = INT_MAX, ver1 = -1, ind1 = -1;
            int mx = -INT_MAX, ver2 = -1, ind2 = -1;
            for (int i = l; i <= r; i++) {
                if (a[i] == v) {
                    ans = { i, i }; break;
                }
                if (upper(v, a[i])) {
                    if (tin[a[i]] < mn) {
                        mn = tin[a[i]]; ver1 = a[i];
                        ind1 = i;
                    }
                    if (tin[a[i]] > mx) {
                        mx = tin[a[i]]; ver2 = a[i];
                        ind2 = i;
                    }
                }
                else {
                    if (ver1 != -1) {
                        if (ind1 > ind2) swap(ind1, ind2);
                        if (lca(ver1, ver2) == v) ans = { ind1, ind2 };
                    }
                }
            }
            if (ver1 != -1) {
                if (ind1 > ind2) swap(ind1, ind2);
                if (lca(ver1, ver2) == v) ans = { ind1, ind2 };
            }
            cout << ans.first << ' ' << ans.second << '\n';
        }
        else {
            int pos, v;
            cin >> pos >> v;
            a[pos] = v;
        }
    }
    return 0;
}

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