Submission #844912

#	Time	Username	Problem	Language	Result	Execution time	Memory
844912		Darren0724	Birthday gift (IZhO18_treearray)	C++17	56 / 100	4030 ms	35932 KiB

treearray

#include <bits/stdc++.h>
using namespace std;
//#define int long long
#define all(x) x.begin(), x.end()
const int N = 200005;
const int K = __lg(N) + 1;
int n, m, q;
vector<int> adj[N], deep(N);
int jump[K][N];
void dfs(int k, int pa) {
    jump[0][k] = pa;
    for (int i = 1; i < K; i++) {
        jump[i][k] = jump[i - 1][jump[i - 1][k]];
    }
    for (int j : adj[k]) {
        if (j == pa) {
            continue;
        }
        deep[j] = deep[k] + 1;
        dfs(j, k);
    }
}
int lca(int a, int b) {
    if (deep[a] < deep[b]) {
        swap(a, b);
    }
    int p = deep[a] - deep[b];
    for (int i = 0; i < K; i++) {
        if ((1 << i) & p) {
            a = jump[i][a];
        }
    }
    if (a == b) {
        return a;
    }
    for (int i = K - 1; i >= 0; i--) {
        if (jump[i][a] != jump[i][b]) {
            a = jump[i][a];
            b = jump[i][b];
        }
    }
    return jump[0][a];
}
int up(int a, int b) {
    return lca(a, b) == b;
}
int32_t main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cin >> n >> m >> q;
    for (int i = 1; i < n; i++) {
        int a, b;
        cin >> a >> b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    dfs(1, 1);
    vector<int> v(m + 1);
    for (int i = 1; i <= m; i++) {
        cin >> v[i];
    }
    for (int i = 0; i < q; i++){
        int id; cin >> id;
        if (id == 1) {
            int a,b;cin>>a>>b;
            v[a]=b;
        } 
        else {
            int a,b,c;cin>>a>>b>>c;
            int y=-1;
            int p=0;
            int ans1=-1,ans2=-1;
            for(int j=a;j<=b;j++){
                if(!up(v[j],c)){
                    y=-1;
                }
                else{
                    if(y==-1){
                        p=j;
                        y=v[j];
                    }
                    else{
                        y=lca(y,v[j]);
                    }
                }
                if(y==c){
                    ans1=p,ans2=j;
                    break;
                }
            }
            cout<<ans1<<' '<<ans2<<endl;
        } 
    }
    return 0;
}

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