Submission #751006

#	Time	Username	Problem	Language	Result	Execution time	Memory
751006		anaduguleanu	Synchronization (JOI13_synchronization)	C++14	100 / 100	650 ms	23240 KiB

synchronization

#include <iostream>
#include <vector>
#define MAX 100000
#define LOG 20
using namespace std;
///ifstream cin ("c.in");
///ofstream cout ("c.out");
vector <int> graph[MAX + 10];
pair <int, int> edges[2 * MAX + 10];
int timer = 1, in[MAX + 10], out[MAX + 10], ancestor[LOG + 10][MAX + 10], tree[MAX + 10], info[MAX + 10], last[MAX + 10], active[MAX + 10];
void update(int pos, int val)
{
    for (int i = pos; i <= MAX; i = i + (i & -i))
        tree[i] = tree[i] + val;
}
int query(int pos)
{
    int ans = 0;
    for (int i = pos; i >= 1; i = i - (i & -i))
        ans = ans + tree[i];
    return ans;
}
void dfs(int node, int parent)
{
    ancestor[0][node] = parent;
    for (int p = 1; p <= LOG && ancestor[p - 1][node] != 0; p++)
        ancestor[p][node] = ancestor[p - 1][ancestor[p - 1][node]];
    info[node] = 1;
    in[node] = timer;
    timer++;
    for (auto next : graph[node])
        if (next != parent)
            dfs(next, node);
    out[node] = timer;
}
int findAncestor(int node)
{
    for (int p = LOG; p >= 0; p--)
        if (ancestor[p][node] != 0 && query(in[ancestor[p][node]]) == query(in[node]))
            node = ancestor[p][node];
    return node;
}
int main()
{
    int n, m, q;
    cin >> n >> m >> q;
    for (int i = 1; i < n; i++)
    {
        int x, y;
        cin >> x >> y;
        graph[x].push_back(y);
        graph[y].push_back(x);
        edges[i] = {x, y};
    }
    dfs(1, 0);
    for (int i = 1; i <= n; i++)
    {
        update(in[i], -1);
        update(out[i], 1);
    }
    for (int i = 1; i <= m; i++)
    {
        int edge;
        cin >> edge;
        int node1 = edges[edge].first, node2 = edges[edge].second;
        if (ancestor[0][node1] == node2)
            swap(node1, node2);
        if (active[edge] == 1)
        {
            info[node2] = last[node2] = info[findAncestor(node1)];
            update(in[node2], -1);
            update(out[node2], 1);
            active[edge] = 0;
        }
        else
        {
            info[findAncestor(node1)] = info[findAncestor(node1)] + info[node2] - last[node2];
            update(in[node2], 1);
            update(out[node2], -1);
            active[edge] = 1;
        }
    }
    for (int i = 1; i <= q; i++)
    {
        int node;
        cin >> node;
        cout << info[findAncestor(node)] << '\n';
    }
    return 0;
}

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