Submission #673269

#	Time	Username	Problem	Language	Result	Execution time	Memory
673269		moday_morning	Birthday gift (IZhO18_treearray)	C++17	100 / 100	938 ms	95300 KiB

treearray

#include <bits/stdc++.h>
#define int long long
using namespace std;

const int  N = 2e5 + 7;
 
int a[N], l[N];
set <int> s[N], s1[N];
vector <int> g[N];
 
int p[N][20], d[N];
 
void dfs (int u, int pa = 0, int depth = 0) {
    p[u][0] = pa;
    for (int i = 1; i < 20; i++) {
        p[u][i] = p[p[u][i - 1]][i - 1];
    }
    d[u] = depth;
    for (int v : g[u]) {
        if(v != pa) {
            dfs(v, u, depth + 1);
        }
    }
}
 
int lca (int u, int v) {
    if (d[u] > d[v]) {
        swap(u, v);
    }
    for (int i = 19; i >= 0; i--) {
        if ((d[v] - d[u]) >> i & 1) {
            v = p[v][i];
        }
    }
    if (u == v) {
        return u;
    }
    for (int i = 19; i >= 0; i--) {
        if (p[u][i] != p[v][i]) {
            u = p[u][i];
            v = p[v][i];
        }
    }
    return p[u][0];
}
 
void solve() {
    int n, m, q;
    cin >> n >> m >> q;
    for(int i = 0; i < n - 1; i++) {
        int u, v;
        cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
    }
    dfs(1);
    for(int i = 1; i <= m; i++) {
        cin >> a[i];
        s1[a[i]].insert(i);
    }
    auto del = [&] (int pos) {
        s[l[pos]].erase(pos);
    };
    auto calc = [&] (int pos) {
        l[pos] = lca(a[pos], a[pos + 1]);
        s[l[pos]].insert(pos);
    };
    for (int i = 1; i < m; i++) {
        calc(i);
    }
    while (q--) {
        int x;
        cin >> x;
        if (x == 1) {
            int i, v;
            cin >> i >> v;
            s1[a[i]].erase(i);
            a[i] = v;
            s1[a[i]].insert(i);
            if (i - 1 >= 1) {
                del(i - 1);
                calc(i - 1);
            }
            if (i + 1 <= m) {
                del(i);
                calc(i);
            }
        }
        else {
            int l, r, v;
            cin >> l >> r >> v;
            auto it = s[v].lower_bound(l);
            if (it != s[v].end() && *it < r) {
                cout << *it << " " << *it + 1 << "\n";
            }
            else {
                auto it = s1[v].lower_bound(l);
                if (it != s1[v].end() && *it <= r) {
                    cout << *it << " " << *it << "\n";
                }
                else {
                    cout << -1 << " " << -1 << "\n";
                }
            }
        }
    }
 
}
signed main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int t = 1;
//    cin >> t;
    while (t--) {
        solve();
    }
}

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