Submission #680725

#	Time	Username	Problem	Language	Result	Execution time	Memory
680725		stevancv	Synchronization (JOI13_synchronization)	C++14	100 / 100	290 ms	23536 KiB

synchronization

#include <bits/stdc++.h>
#define ll long long
#define ld long double
#define sp ' '
#define en '\n'
#define smin(a, b) a = min(a, b)
#define smax(a, b) a = max(a, b)
#define sadd(a, b) a = Add(a, b)
#define smul(a, b) a = Mul(a, b)
using namespace std;
const int N = 1e5 + 2;
vector<int> g[N];
int in[N], out[N], par[N][17], tsz;
int u[N], v[N], ans[N], sync[N];
bool active[N];
void Dfs(int s, int e) {
    in[s] = ++tsz;
    par[s][0] = e;
    for (int i = 1; i < 17; i++) par[s][i] = par[par[s][i - 1]][i - 1];
    for (auto u : g[s]) {
        if (u == e) continue;
        Dfs(u, s);
    }
    out[s] = ++tsz;
}
int bit[2 * N];
void Add(int x, int v) {
    for (; x < 2 * N; x += x & (-x)) bit[x] += v;
}
int Get(int x) {
    int ans = 0;
    for (; x > 0; x -= x & (-x)) ans += bit[x];
    return ans;
}
int Getroot(int x) {
    for (int i = 16; i >= 0; i--) {
        if (par[x][i] && Get(in[par[x][i]]) == Get(in[x])) x = par[x][i];
    }
    return x;
}
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int n, m, q;
    cin >> n >> m >> q;
    for (int i = 1; i < n; i++) {
        cin >> u[i] >> v[i];
        g[u[i]].push_back(v[i]);
        g[v[i]].push_back(u[i]);
    }
    Dfs(1, 0);
    for (int i = 1; i <= n; i++) {
        ans[i] = 1;
        Add(in[i], 1);
        Add(out[i], -1);
    }
    for (int i = 1; i < n; i++) if (in[u[i]] > in[v[i]]) swap(u[i], v[i]);
    while (m--) {
        int i; cin >> i;
        if (active[i] == 0) {
            ans[Getroot(u[i])] += ans[v[i]] - sync[v[i]];
            Add(in[v[i]], -1); Add(out[v[i]], 1);
        }
        else {
            ans[v[i]] = sync[v[i]] = ans[Getroot(u[i])];
            Add(in[v[i]], 1); Add(out[v[i]], -1);
        }
        active[i] = 1 - active[i];
    }
    while (q--) {
        int x; cin >> x;
        cout << ans[Getroot(x)] << en;
    }
    return 0;
}

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