Submission #175528

#	Time	Username	Problem	Language	Result	Execution time	Memory
175528		VEGAnn	Birthday gift (IZhO18_treearray)	C++14	0 / 100	24 ms	23868 KiB

treearray

#include <bits/stdc++.h>
#define sz(x) ((int)x.size())
#define PB push_back
using namespace std;
const int N = 200100;
const int PW = 20;
set<int> st[N], pr[N];
set<int>::iterator it;
vector<int> g[N];
int tin[N], tout[N], up[N][PW], n, m, q, tt = 0, a[N];

void dfs(int v, int p){
    up[v][0] = p;
    for (int po = 1; po < PW; po++)
        up[v][po] = up[up[v][po - 1]][po - 1];

    tin[v] = tt++;

    for (int u : g[v]){
        if (u == p) continue;
        dfs(u, v);
    }

    tout[v] = tt++;
}

bool upper(int a, int b){
    return (tin[a] <= tin[b] && tout[a] >= tout[b]);
}

int lca(int a, int b){
    if (upper(a, b)) return a;
    if (upper(b, a)) return b;

    for (int po = PW - 1; po >= 0; po--)
        if (!upper(up[a][po], b))
            a = up[a][po];

    return up[a][0];
}

int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);

    cin >> n >> m >> q;
    for (int i = 1; i < n; i++){
        int x, y; cin >> x >> y;
        x--; y--;
        g[x].PB(y);
        g[y].PB(x);
    }

    dfs(0, 0);

    for (int i = 0; i < m; i++){
        cin >> a[i];
        a[i]--;
        st[a[i]].insert(i);

        if (i > 0)
            pr[lca(a[i], a[i - 1])].insert(i);
    }

    for (; q; q--){
        int tp;
        cin >> tp;
        if (tp == 1){
            int ps, v; cin >> ps >> v;
            ps--; v--;
            st[a[ps]].erase(ps);
            if (ps > 0)
                pr[lca(a[ps], a[ps - 1])].erase(ps);
            if (ps + 1 < m)
                pr[lca(a[ps], a[ps + 1])].erase(ps + 1);

            a[ps] = v;

            st[a[ps]].insert(ps);
            if (ps > 0)
                pr[lca(a[ps], a[ps - 1])].insert(ps);
            if (ps + 1 < m)
                pr[lca(a[ps], a[ps + 1])].insert(ps + 1);
        } else {
            int l, r, v; cin >> l >> r >> v;
            l--; r--; v--;
            int x = -2, y = -2;
            if (sz(st[v])){
                it = st[v].lower_bound(l);
                if (it != st[v].end() && (*it) <= r){
                    y = x = (*it);
                }
            }

            if (x < 0 && sz(pr[v])){
                it = pr[v].lower_bound(l);
                if (it != pr[v].end() && (*it) <= r){
                    y = (*it);
                    x = y - 1;
                }
            }

            cout << x + 1 << " " << y + 1 << '\n';
        }
    }

    return 0;
}

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