Submission #886316

#	Time	Username	Problem	Language	Result	Execution time	Memory
886316		boris_mihov	Birthday gift (IZhO18_treearray)	C++17	100 / 100	1169 ms	84740 KiB

treearray

#include <algorithm>
#include <iostream>
#include <numeric>
#include <cassert>
#include <bitset>
#include <vector>
#include <stack>
#include <set>

typedef long long llong;
const int MAXN = 200000 + 10;
const int MAXLOG = 18;

int n, m, q;
struct Sparse
{
    int sparse[MAXLOG][MAXN];
    int depth[MAXN];
    int par[MAXN];

    void build(int _depth[], int _par[])
    {
        for (int i = 1 ; i <= n ; ++i)
        {
            par[i] = _par[i];
            depth[i] = _depth[i];
            sparse[0][i] = par[i];
        }

        for (int log = 1 ; (1 << log) <= n ; ++log)
        {
            for (int i = 1 ; i <= n ; ++i)
            {
                sparse[log][i] = sparse[log - 1][sparse[log - 1][i]];
            }
        }
    }

    int equalize(int x, int y)
    {
        for (int log = MAXLOG - 1 ; log >= 0 ; --log)
        {
            if (depth[sparse[log][x]] >= depth[y])
            {
                x = sparse[log][x];
            }
        }

        return x;
    }

    int calcLCA(int x, int y)
    {
        if (x == y)
        {
            return x;
        }

        for (int log = MAXLOG - 1 ; log >= 0 ; --log)
        {
            if (sparse[log][x] != sparse[log][y])
            {
                x = sparse[log][x];
                y = sparse[log][y];
            }
        }

        return sparse[0][x];
    }

    int findLCA(int x, int y)
    {
        if (depth[x] < depth[y])
        {
            std::swap(x, y);
        }

        return calcLCA(equalize(x, y), y);
    }
};

int a[MAXN];
Sparse sparse;
int par[MAXN];
int depth[MAXN];
std::set <int> byLCA[MAXN];
std::set <int> byLCA2[MAXN];
std::vector <int> g[MAXN];

void dfs(int node, int p)
{
    par[node] = p;
    depth[node] = depth[p] + 1;
    
    for (const int &u : g[node])
    {
        if (u == p)
        {
            continue;
        }

        dfs(u, node);
    }
}

void solve()
{   
    dfs(1, 0);
    sparse.build(depth, par);

    for (int i = 1 ; i <= m ; ++i)
    {
        byLCA[a[i]].insert(i);
        if (i != m)
        {
            byLCA2[sparse.findLCA(a[i], a[i + 1])].insert(i);
        }
    }

    for (int query = 1 ; query <= q ; ++query)
    {
        int qType;
        std::cin >> qType;

        if (qType == 1)
        {
            int pos, node;
            std::cin >> pos >> node;
            byLCA[a[pos]].erase(byLCA[a[pos]].find(pos));
            
            if (pos < m)
            {
                int lca = sparse.findLCA(a[pos], a[pos + 1]);
                byLCA2[lca].erase(byLCA2[lca].find(pos));
            }

            if (pos > 1)
            {
                int lca = sparse.findLCA(a[pos], a[pos - 1]);
                byLCA2[lca].erase(byLCA2[lca].find(pos - 1));
            }

            a[pos] = node;
            byLCA[a[pos]].insert(pos);

            if (pos < m)
            {
                int lca = sparse.findLCA(a[pos], a[pos + 1]);
                byLCA2[lca].insert(pos);
            }

            if (pos > 1)
            {
                int lca = sparse.findLCA(a[pos], a[pos - 1]);
                byLCA2[lca].insert(pos - 1);
            }

            continue;
        }

        int l, r, node;
        std::cin >> l >> r >> node;

        auto it = byLCA[node].lower_bound(l);
        if (it != byLCA[node].end() && (*it) <= r)
        {
            std::cout << (*it) << ' ' << (*it) << '\n';
            continue;
        }

        it = byLCA2[node].lower_bound(l);
        if (it != byLCA2[node].end() && (*it) < r)
        {
            std::cout << (*it) << ' ' << (*it) + 1 << '\n';
            continue;
        }

        std::cout << -1 << ' ' << -1 << '\n';
    } 
}

void input()
{
    std::cin >> n >> m >> q;
    for (int i = 2 ; i <= n ; ++i)
    {
        int u, v;
        std::cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }

    for (int i = 1 ; i <= m ; ++i)
    {
        std::cin >> a[i];
    }
}

void fastIOI()
{
    std::ios_base :: sync_with_stdio(0);
    std::cout.tie(nullptr);
    std::cin.tie(nullptr);
}

int main()
{
    fastIOI();
    input();
    solve();

    return 0;
}

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