Submission #1100605

#	Time	Username	Problem	Language	Result	Execution time	Memory
1100605		vjudge1	Birthday gift (IZhO18_treearray)	C++98	30 / 100	4074 ms	9024 KiB

treearray

#include <bits/stdc++.h>
using namespace std;
const int N = 200005, M = 20;
int up[N][M], dep[N], tin[N], tout[N], timer = 0;
int a[N];
vector<int> adj[N];
//dfs
void dfs(int v, int p)
{
    tin[v] = ++timer;
    up[v][0] = p;
    for(int i = 1; i < M; i++)
    {
        up[v][i] = up[up[v][i - 1]][i - 1];
    }
    for(int u : adj[v]) 
    {
        if(u != p)
        {
            dep[u] = dep[v] + 1;
            dfs(u, v);
        }
    }
    tout[v] = ++timer;
}
// предок па?
bool is(int v, int u)
{
    return tin[v] <= tin[u] && tout[v] >= tout[u];
}
//наименьший общий предок иуу
int lca(int u, int v)
{
    if(is(u, v))
    {
        return u;
    }
    if(is(v, u))
    {
        return v;
    }
    for(int i = M - 1; i >= 0; i--)
    {
        if(!is(up[u][i], v)) 
        {
            u = up[u][i];
        }
    }
    return up[u][0];
}
int main()
{
    int n, m, q;
    cin >> n >> m >> q;
    for(int i = 1; i < n; i++)
    {
        int u, v;
        cin >> u >> v;
        adj[u].push_back(v);
        adj[v].push_back(u);
    }
    dfs(1, 1);
    for(int i = 0; i < m; i++)
    {
        cin >> a[i];
    }
    for(int i = 0; i < q; i++)
    {
        int tp;
        cin >> tp;
        //запрашиваем типы
        if(tp == 1)
        {
            int pos, v;
            cin >> pos >> v;
            pos--;
            a[pos] = v;
        }
        else if(tp == 2) 
        {
            int l, r, v;
            cin >> l >> r >> v;
            l--;
            r--;
            bool ok = false;
            for(int x = l; x <= r && !ok; x++)
            {
                int cur = a[x];
                for(int y = x; y <= r; y++)
                {
                    cur = lca(cur, a[y]);
                    if(cur == v)
                    {
                        cout << x + 1 << " " << y + 1 << endl;
                        ok = true;
                        break;
                    }
                }
            }
            if(!ok)
            {
                cout << -1 << " " << -1 << endl;
            }
        }
    }
}

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