제출 #896091

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
896091		borisAngelov	Birthday gift (IZhO18_treearray)	C++17	100 / 100	729 ms	84120 KiB

treearray

#include <bits/stdc++.h>

using namespace std;

const int maxn = 200005;
const int maxlog = 19;

int n, m, q;

vector<int> tree[maxn];

int jump[maxn][maxlog + 1];
int depth[maxn];

void dfsLCA(int node, int par, int dep)
{
    depth[node] = dep;

    for (int i = 0; i < tree[node].size(); ++i)
    {
        if (tree[node][i] != par)
        {
            dfsLCA(tree[node][i], node, dep + 1);
            jump[tree[node][i]][0] = node;
        }
    }
}

void buildSparse()
{
    jump[1][0] = 1;

    for (int log = 1; log <= maxlog; ++log)
    {
        for (int node = 1; node <= n; ++node)
        {
            jump[node][log] = jump[jump[node][log - 1]][log - 1];
        }
    }
}

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

    int diff = depth[x] - depth[y];

    for (int i = 0; i <= maxlog; ++i)
    {
        if ((diff & (1 << i)) != 0)
        {
            x = jump[x][i];
            diff -= (1 << i);

            if (diff == 0)
            {
                break;
            }
        }
    }

    if (x == y)
    {
        return x;
    }

    for (int log = maxlog; log >= 0; --log)
    {
        if (jump[x][log] != jump[y][log])
        {
            x = jump[x][log];
            y = jump[y][log];
        }
    }

    return jump[x][0];
}

int sequence[maxn];

set<int> byValue[maxn];
set<int> byLCA[maxn];

void updateQuery(int pos, int newNode)
{
    int curr = sequence[pos];

    byValue[curr].erase(pos);

    if (pos >= 2)
    {
        int prv = sequence[pos - 1];
        //cout << "delete LCA " << findLCA(prv, curr) << " on pos " << pos << endl;
        //cout << "add LCA " << findLCA(prv, newNode) << " on pos " << pos << endl;
        byLCA[findLCA(prv, curr)].erase(pos);
        byLCA[findLCA(prv, newNode)].insert(pos);
    }

    if (pos <= m - 1)
    {
        int nxt = sequence[pos + 1];
        //cout << "delete LCA " << findLCA(curr, nxt) << " on pos " << pos + 1 << endl;
        //cout << "add LCA " << findLCA(newNode, nxt) << " on pos " << pos + 1 << endl;
        byLCA[findLCA(curr, nxt)].erase(pos + 1);
        byLCA[findLCA(newNode, nxt)].insert(pos + 1);
    }

    sequence[pos] = newNode;
    byValue[sequence[pos]].insert(pos);
}

void solveQuery(int from, int to, int nodeLCA)
{
    if (!byValue[nodeLCA].empty())
    {
        auto it = byValue[nodeLCA].lower_bound(from);

        if (it != byValue[nodeLCA].end() && (*it) <= to)
        {
            int idx = (*it);
            cout << idx << ' ' << idx << "\n";
            return;
        }
    }

    if (!byLCA[nodeLCA].empty())
    {
        auto it = byLCA[nodeLCA].lower_bound(from + 1);

        if (it != byLCA[nodeLCA].end() && (*it) <= to)
        {
            int idx = (*it);
            cout << idx - 1 << ' ' << idx << "\n";
            return;
        }
    }

    cout << -1 << ' ' << -1 << "\n";
}

void fastIO()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
}

int main()
{
    fastIO();

    cin >> n >> m >> q;

    for (int i = 1; i <= n - 1; ++i)
    {
        int x, y;
        cin >> x >> y;

        tree[x].push_back(y);
        tree[y].push_back(x);
    }

    dfsLCA(1, -1, 0);
    buildSparse();

    for (int i = 1; i <= m; ++i)
    {
        cin >> sequence[i];
        byValue[sequence[i]].insert(i);
    }

    for (int i = 2; i <= m; ++i)
    {
        //cout << "add " << findLCA(sequence[i - 1], sequence[i]) << " on position " << i << endl;
        byLCA[findLCA(sequence[i - 1], sequence[i])].insert(i);
    }

    while (q--)
    {
        int type;
        cin >> type;

        if (type == 1)
        {
            int pos, val;
            cin >> pos >> val;
            updateQuery(pos, val);
        }
        else
        {
            int l, r, node;
            cin >> l >> r >> node;
            solveQuery(l, r, node);
        }
    }

    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

treearray.cpp: In function 'void dfsLCA(int, int, int)':
treearray.cpp:19:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |     for (int i = 0; i < tree[node].size(); ++i)
      |                     ~~^~~~~~~~~~~~~~~~~~~

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