Submission #963630

#	Time	Username	Problem	Language	Result	Execution time	Memory
963630		Ghetto	The Potion of Great Power (CEOI20_potion)	C++17	100 / 100	2557 ms	46724 KiB

potion

#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
const int MAX_N = 1e5 + 5, K = 50, MAX_T = 2e5 + 5;
 
int n;
int h[MAX_N]; // Not id
int t;
int e1[MAX_T], e2[MAX_T]; // Not id
 
int id[MAX_N], rev_id[MAX_N]; 
vector<pii> upds[MAX_N]; // {time, node} and {0, -1}
set<int> adj[MAX_N]; // reused
vector<vector<int>> crit_adjs[MAX_N];
void update1(int u, int v, set<int>& s) { // one-way
    if (s.count(v)) s.erase(v);
    else s.insert(v);
}
void save(int u) {
    vector<int> cur_adj(adj[u].begin(), adj[u].end());
    crit_adjs[u].push_back(cur_adj);
}
void precomp() {
    vector<pii> order;
    for (int i = 0; i < n; i++) order.push_back({h[i], i});
    sort(order.begin(), order.end());
    for (int i = 0; i < n; i++) {
        id[order[i].second] = i;
        rev_id[i] = order[i].second;
    }
 
    for (int upd = 0; upd <= t; upd++) {
        if (upd == 0) {
            for (int u = 0; u < n; u++) {
                upds[u].push_back({0, -1});
                save(u);
            }
            continue;
        }
 
        int u = id[e1[upd]], v = id[e2[upd]];
        update1(u, v, adj[u]);
        update1(v, u, adj[v]);
        upds[u].push_back({upd, v});
        upds[v].push_back({upd, u});
 
        if (((int) upds[u].size() - 1) % K == 0) save(u);
        if (((int) upds[v].size() - 1) % K == 0) save(v);
    }
}
 
void init(int tmp_n, int tmp_d, int tmp_h[]) {
    n = tmp_n;
    for (int i = 0; i < n; i++) h[i] = tmp_h[i];
}
void curseChanges(int tmp_t, int tmp_e1[], int tmp_e2[]) {
    t = tmp_t;
    for (int i = 1; i <= t; i++) {
        e1[i] = tmp_e1[i - 1];
        e2[i] = tmp_e2[i - 1];
    }
    precomp();
}
 
set<int> update2(int u, int upd) {
    // First update with time <= upd
    int hi = upper_bound(upds[u].begin(), upds[u].end(), make_pair(upd, (int) 1e9)) - upds[u].begin() - 1; 
    int lo = K * (hi / K);
    set<int> cur_adj(crit_adjs[u][hi / K].begin(), crit_adjs[u][hi / K].end());
 
    for (int i = lo + 1; i <= hi; i++) 
        update1(u, upds[u][i].second, cur_adj);
    return cur_adj;
}
int question(int u, int v, int upd) {
    u = id[u]; 
    v = id[v];
 
    set<int> u_adj(update2(u, upd));
    set<int> v_adj(update2(v, upd));   
 
    int ans = 1e9;
    auto u_it = u_adj.begin(), v_it = v_adj.begin();
    while (u_it != u_adj.end() && v_it != v_adj.end()) {
        int u_h = h[rev_id[*u_it]], v_h = h[rev_id[*v_it]];

        ans = min(ans, abs(u_h - v_h));
        if (u_h <= v_h) u_it++;
        else v_it++;
    }
    return ans;
}

• Subtask 1: 0 / 0
• Subtask 2: 17 / 17
• Subtask 3: 14 / 14
• Subtask 4: 18 / 18
• Subtask 5: 21 / 21
• Subtask 6: 30 / 30