Submission #378894

#	Time	Username	Problem	Language	Result	Execution time	Memory
378894		syl123456	Birthday gift (IZhO18_treearray)	C++17	56 / 100	4081 ms	38508 KiB

treearray

#include <bits/stdc++.h>
#define all(i) i.begin(), i.end()
#define rall(i) i.rbegin(), i.rend()
using namespace std;
typedef long long ll;
typedef pair<int, int> pi;
vector<vector<int>> g, pa;
vector<int> dep;
void dfs(int i, int p) {
    for (int j : g[i]) if (j != p)
        dep[j] = dep[i] + 1, pa[j][0] = i, dfs(j, i);
}
int lca(int i, int j) {
    if (dep[i] < dep[j]) swap(i, j);
    for (int ii = 11; ~ii; --ii) if (dep[pa[i][ii]] >= dep[j])
            i = pa[i][ii];
    for (int ii = 11; ~ii; --ii) if (pa[i][ii] != pa[j][ii])
            i = pa[i][ii], j = pa[j][ii];
    return i == j ? i : pa[i][0];
}
int main() {
    ios::sync_with_stdio(0), cin.tie(0);
    int n, m, q;
    cin >> n >> m >> q;
    g.resize(n), pa.assign(n, vector<int>(12)), dep.resize(n);;
    for (int i = 0; i < n - 1; ++i) {
        int x, y;
        cin >> x >> y;
        --x, --y;
        g[x].push_back(y), g[y].push_back(x);
    }
    dep[0] = 0, pa[0][0] = 0;
    dfs(0, 0);
    for (int i = 1; i < 12; ++i)
        for (int j = 0; j < n; ++j)
            pa[j][i] = pa[pa[j][i - 1]][i - 1];
    int a[m];
    for (int &i : a) cin >> i, --i;
    while (q--) {
        int ty, x, y, z;
        cin >> ty >> x >> y;
        if (ty == 1) {
            a[x - 1] = y - 1;
            continue;
        }
        cin >> z;
        --x, --z;
        int l = -1, now = -1;
        bool fail = true;
        for (int r = x; r < y; ++r) {
            if (a[r] == z) {
                cout << r + 1 << ' ' << r + 1 << '\n';
                fail = false;
                break;
            }
            if (now == -1) {
                int tmp = lca(a[r], z);
                if (tmp == z)
                    l = r, now = a[r];
            } else {
                int tmp = lca(now, a[r]);
                if (tmp == z) {
                    cout << l + 1 << ' ' << r + 1 << '\n';
                    fail = false;
                    break;
                }
                if (lca(tmp, z) == z)
                    now = tmp;
                else
                    l = now = -1;
            }
        }
        if (fail) cout << "-1 -1\n";
    }
}

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