Submission #379387

#	Time	Username	Problem	Language	Result	Execution time	Memory
379387		syl123456	Birthday gift (IZhO18_treearray)	C++17	0 / 100	1 ms	364 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> d;
void dfs(int i, int p) {
    for (int j : g[i]) if (j != p)
        d[j] = d[i] + 1, pa[j][0] = i, dfs(j, i);
}
int lca(int i, int j) {
    if (d[i] < d[j]) swap(i, j);
    for (int ii = 19; ~ii; --ii) if (d[pa[i][ii]] >= d[j])
            i = pa[i][ii];
    for (int ii = 19; ~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>(20)), d.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);
    }
    pa[0][0] = d[0] = 0;
    dfs(0, 0);
    for (int i = 1; i < 20; ++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;
    set<int> s[n], s1[n];
    for (int i = 1; i < m; ++i) s[lca(a[i], a[i - 1])].insert(i - 1);
    for (int i = 0; i < m; ++i) s1[a[i]].insert(i);
    while (q--) {
        int ty, x, y, z;
        cin >> ty >> x >> y;
        --x, --y;
        if (ty == 1) {
            if (x) s[lca(a[x], a[x - 1])].erase(x - 1);
            if (x < m - 1) s[lca(a[x], a[x + 1])].erase(x);
            s1[a[x]].erase(x);
            a[x] = y;
            if (x) s[lca(a[x], a[x - 1])].insert(x - 1);
            if (x < m - 1) s[lca(a[x], a[x + 1])].insert(x);
            s1[a[x]].insert(x);
        }
        else {
            cin >> z;
            --z;
            auto it = s1[z].lower_bound(x);
            if (it != s1[z].end() && *it <= y) {
                cout << *it + 1 << ' ' << *it + 1 << '\n';
                continue;
            }
            it = s[z].lower_bound(x);
            if (it != s[z].lower_bound(y))
                cout << "-1 -1\n";
            else cout << *it + 1 << ' ' << *it + 2 << '\n';
        }
    }
}

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