Submission #1047521

#	Time	Username	Problem	Language	Result	Execution time	Memory
1047521		vladilius	Synchronization (JOI13_synchronization)	C++17	100 / 100	124 ms	24264 KiB

synchronization

#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int, int>;
#define pb push_back
#define ff first
#define ss second
#define arr3 array<int, 3>

struct ST{
    vector<int> t;
    int n;
    ST(int ns){
        n = ns;
        t.resize(4 * n);
    }
    void upd(int v, int tl, int tr, int& p, bool& k){
        if (tl == tr){
            t[v] = k;
            return;
        }
        int tm = (tl + tr) / 2, vv = 2 * v;
        if (p <= tm){
            upd(vv, tl, tm, p, k);
        }
        else {
            upd(vv + 1, tm + 1, tr, p, k);
        }
        t[v] = min(t[vv], t[vv + 1]);
    }
    void upd(int p, bool k){
        upd(1, 1, n, p, k);
    }
    vector<arr3> all;
    void dec(int v, int tl, int tr, int& l, int& r){
        if (l > tr || r < tl) return;
        if (l <= tl && tr <= r){
            all.pb({v, tl, tr});
            return;
        }
        int tm = (tl + tr) / 2, vv = 2 * v;
        dec(vv + 1, tm + 1, tr, l, r);
        dec(vv, tl, tm, l, r);
    }
    int find(int v, int tl, int tr){
        if (tl == tr) return tl;
        int tm = (tl + tr) / 2, vv = 2 * v;
        if (!t[vv + 1]) return find(vv + 1, tm + 1, tr);
        return find(vv, tl, tm);
    }
    int find(int l, int r){
        all.clear();
        dec(1, 1, n, l, r);
        for (auto [v, tl, tr]: all){
            if (!t[v]){
                return find(v, tl, tr);
            }
        }
        return 0;
    }
};

int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    
    int n, m, q; cin>>n>>m>>q;
    vector<int> g[n + 1];
    vector<pii> ed = {{}};
    for (int i = 1; i < n; i++){
        int x, y; cin>>x>>y;
        ed.pb({x, y});
        g[x].pb(y);
        g[y].pb(x);
    }
    
    vector<int> sz(n + 1), h(n + 1), d(n + 1), p(n + 1);
    function<void(int, int)> fill = [&](int v, int pr){
        p[v] = pr;
        sz[v] = 1;
        d[v] = d[pr] + 1;
        for (int i: g[v]){
            if (i == pr) continue;
            fill(i, v);
            if (sz[i] > sz[h[v]]){
                h[v] = i;
            }
            sz[v] += sz[i];
        }
    };
    fill(1, 0);
    
    vector<int> head(n + 1), pos(n + 1);
    int timer = 0;
    function<void(int, int)> fill_hld = [&](int v, int k){
        head[v] = k;
        pos[v] = ++timer;
        if (!h[v]) return;
        fill_hld(h[v], k);
        for (int i: g[v]){
            if (pos[i]) continue;
            fill_hld(i, i);
        }
    };
    fill_hld(1, 1);
    
    vector<int> inv(n + 1);
    for (int i = 1; i <= n; i++) inv[pos[i]] = i;
    
    for (int i = 1; i < ed.size(); i++){
        if (d[ed[i].ff] > d[ed[i].ss]){
            swap(ed[i].ff, ed[i].ss);
        }
    }
    
    vector<bool> used(n + 1);
    vector<int> last(n + 1), out(n + 1, 1);
    
    ST T(n);
    auto get = [&](int v){
        while (true){
            int u = T.find(pos[head[v]], pos[v]);
            if (u > 0) return inv[u];
            v = p[head[v]];
        }
    };
    
    while (m--){
        int p; cin>>p;
        auto [u, v] = ed[p];
        if (used[p]){
            out[v] = last[v] = out[get(u)];
            T.upd(pos[v], 0);
        }
        else {
            out[get(u)] += (out[v] - last[v]);
            T.upd(pos[v], 1);
        }
        used[p] = !used[p];
    }
    while (q--){
        int x; cin>>x;
        cout<<out[get(x)]<<"\n";
    }
}

Compilation message (stderr)

synchronization.cpp: In function 'int main()':
synchronization.cpp:111:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  111 |     for (int i = 1; i < ed.size(); i++){
      |                     ~~^~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 20 / 20
• Subtask 3: 10 / 10
• Subtask 4: 20 / 20
• Subtask 5: 40 / 40