Submission #984352

#	Time	Username	Problem	Language	Result	Execution time	Memory
984352		LOLOLO	Synchronization (JOI13_synchronization)	C++17	100 / 100	194 ms	26088 KiB

synchronization

#include <bits/stdc++.h>
#define ll long long
using namespace std;
 
#define           f     first
#define           s     second
#define           pb    push_back
#define           ep    emplace
#define           eb    emplace_back
#define           lb    lower_bound
#define           ub    upper_bound
#define       all(x)    x.begin(), x.end()
#define      rall(x)    x.rbegin(), x.rend()
#define   uniquev(v)    sort(all(v)), (v).resize(unique(all(v)) - (v).begin())
#define     mem(f,x)    memset(f , x , sizeof(f))
#define        sz(x)    (int)(x).size()
#define  __lcm(a, b)    (1ll * ((a) / __gcd((a), (b))) * (b))
#define          mxx    *max_element
#define          mnn    *min_element
#define    cntbit(x)    __builtin_popcountll(x)
#define       len(x)    (int)(x.length())
 
const int N = 1e5 + 10;
vector <int> ed[N];
int p[N][20], f[N], in[N], ou[N], timer = 1, num[N], pr[N], used[N];

void upd(int i, int x) {
    for (; i < N; i += i & (-i))
        f[i] += x;
}

int get(int i) {
    int s = 0;
    for (; i; i -= i & (-i))
        s += f[i];

    return s;
} 

void dfs(int u, int v) {
    in[u] = timer++;
    p[u][0] = v;
    for (int j = 1; j < 20; j++)
        p[u][j] = p[p[u][j - 1]][j - 1];

    for (auto x : ed[u]) {
        if (x == v)
            continue;

        dfs(x, u);
    }

    ou[u] = timer;
    upd(in[u], 1);
    upd(ou[u], -1);
}

int root(int x) {
    int v = get(in[x]);

    for (int j = 19; j >= 0; j--) {
        if (get(in[p[x][j]]) == v)
            x = p[x][j];
    }

    return x;
}

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

    int n, m, q;
    cin >> n >> m >> q;

    vector <pair <int, int>> save;
    for (int i = 1; i < n; i++) {
        int a, b;
        cin >> a >> b;
        ed[a].pb(b);
        ed[b].pb(a);
        save.pb({a, b});
    }

    dfs(1, 1);

    for (int i = 1; i <= n; i++) {
        num[i] = 1;
    }

    for (int i = 1; i <= m; i++) {
        int id;
        cin >> id;
        id--;
        int a = save[id].f, b = save[id].s;
        if (p[a][0] == b)
            swap(a, b);

        if (used[id] == -1) {
            // remove edge
            int r = root(a);
            upd(in[b], 1);
            upd(ou[b], -1);
            num[b] = used[id] = num[r];
        } else {
            // insert edge
            int r = root(a);
            upd(in[b], -1);
            upd(ou[b], 1);
            num[r] += abs(num[b] - used[id]);
            used[id] = -1;
        } 
    }

    for (int i = 0; i < q; i++) {
        int x;
        cin >> x;
        cout << num[root(x)] << '\n';
    }

    return 0;
}   

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