Submission #447324

#	Time	Username	Problem	Language	Result	Execution time	Memory
447324		tranxuanbach	Birthday gift (IZhO18_treearray)	C++17	56 / 100	4091 ms	33636 KiB

treearray

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

#define endl '\n'
#define fi first
#define se second
#define For(i, l, r) for (int i = l; i < r; i++)
#define ForE(i, l, r) for (int i = l; i <= r; i++)
#define FordE(i, l, r) for (int i = l; i >= r; i--)
#define Fora(v, a) for (auto v: a)
#define bend(a) a.begin(), a.end()
#define isz(a) ((signed)a.size())

using ll = long long;
using ld = long double;
using pii = pair <int, int>;
using vi = vector <int>;
using vpii = vector <pii>;
using vvi = vector <vi>;

const int N = 2e5 + 5, M = __lg(N) + 2;

int n, m, q;
vi adj[N];
int a[N];

int h[N];
int ctrtime, tin[N], tout[N];
int lift[N][M];

void dfs_tour(int u, int p){
    tin[u] = tout[u] = ++ctrtime;
    Fora(&v, adj[u]){
        if (v == p){
            continue;
        }
        h[v] = h[u] + 1;
        dfs_tour(v, u);
        tout[u] = ++ctrtime;
    }
}

void dfs_lift(int u, int p){
    lift[u][0] = p;
    For(i, 1, M){
        lift[u][i] = lift[lift[u][i - 1]][i - 1];
    }
    Fora(&v, adj[u]){
        if (v == p){
            continue;
        }
        dfs_lift(v, u);
    }
}

int lca(int u, int v){
    if (h[u] < h[v]){
        swap(u, v);
    }
    FordE(i, M - 1, 0){
        if (h[u] - (1 << i) >= h[v]){
            u = lift[u][i];
        }
    }
    if (u == v){
        return u;
    }
    FordE(i, M - 1, 0){
        if (lift[u][i] != lift[v][i]){
            u = lift[u][i];
            v = lift[v][i];
        }
    }
    return lift[u][0];
}

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    // freopen(".inp", "r", stdin);
    // freopen(".out", "w", stdout);
    cin >> n >> m >> q;
    For(i, 1, n){
        int u, v; cin >> u >> v;
        adj[u].emplace_back(v);
        adj[v].emplace_back(u);
    }
    ForE(i, 1, m){
        cin >> a[i];
    }
    dfs_tour(1, 1);
    dfs_lift(1, 1);
    while (q--){
        int que; cin >> que;
        if (que == 1){
            int pos, u; cin >> pos >> u;
            a[pos] = u;
        }
        else{
            int l, r, u; cin >> l >> r >> u;
            int ansx = -1, ansy = -1;
            int v = -1, x = -1;
            ForE(y, l, r){
                if (!(tin[u] <= tin[a[y]] and tout[a[y]] <= tout[u])){
                    v = -1;
                    x = -1;
                    continue;
                }
                if (v == -1){
                    v = a[y];
                    x = y;
                }
                else{
                    v = lca(v, a[y]);
                }
                if (v == u){
                    ansx = x; ansy = y;
                }
            }
            cout << ansx << ' ' << ansy << endl;
        }
    }
}

/*
==================================================+
INPUT:                                            |
--------------------------------------------------|
5 4 4
1 2
3 1
3 4
5 3
4 5 2 3
2 1 3 1
1 3 5
2 3 4 5
2 1 3 1

--------------------------------------------------|
==================================================+
OUTPUT:                                           |
--------------------------------------------------|
1 3
3 3
-1 -1
--------------------------------------------------|
==================================================+
*/

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