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Submission #220759

# Submission time Handle Problem Language Result Execution time Memory
220759 2020-04-08T17:48:58 Z tictaccat Synchronization (JOI13_synchronization) C++14
30 / 100
 584 ms 23436 KB 
#include <bits/stdc++.h>

using namespace std;

const int MAX = 1e5 + 100;

int N,M,Q,C;
vector<vector<int>> adj(MAX);
vector<pair<int,int>> el;
vector<bool> active(MAX);

int cnt;
vector<int> p(MAX), explored(MAX), pre(MAX), post(MAX), dep(MAX);
vector<vector<int>> anc(20, vector<int>(MAX));
vector<int> a(MAX, 1), c(MAX,0);

vector<int> tr(MAX);

void dfs(int u) {
    explored[u] = true;
    pre[u] = cnt++;
    for (int v: adj[u]) {
        if (explored[v]) continue;
        p[v] = u;
        dep[v] = dep[u]+1;
        dfs(v);
    }
    post[u] = cnt-1;
   // cout << u+1 << " " << pre[u] << " " << post[u] << "\n";
}

void add(int i, int x) {
    i++;
    while (i <= N) {
        tr[i] += x;
        i += i&-i;
    }
}
int sum(int i) {
    i++;
    int s = 0;
    while (i > 0) {
        s += tr[i];
        i -= i&-i;
    }
    return s;
} 

void add_edge(int u, int v) {
    add(pre[u],v);
    add(post[u]+1,-v);
}

int num_edges(int u) {
    return sum(pre[u]);
}

bool connect(int u, int v) {
    return (num_edges(u) - num_edges(v)) == (dep[u] - dep[v]);
}

int find_root(int v) {
    int root = v;
    for (int k = 19; k >= 0; k--) {
        while (connect(anc[k][root], root) && root != C) root = anc[k][root];
    }
    return root;
}

int main() {

    cin >> N >> M >> Q;

    for (int i = 0; i < N-1; i++) {
        int X,Y;
        cin >> X >> Y;
        X--; Y--;
        adj[X].push_back(Y);
        adj[Y].push_back(X);
        el.emplace_back(X,Y);
    }

    vector<int> darr(M);
    for (int i = 0; i < M; i++) {
        cin >> darr[i];
        darr[i]--;
    }

    cin >> C;
    C--;
    dfs(C);
    p[C] = C;

    for (int i = 0; i < N; i++) {
        anc[0][i] = p[i];
    }
    for (int k = 1; k < 20; k++) {
        for (int i = 0; i < N; i++) {
            anc[k][i] = anc[k-1][anc[k-1][i]];
        }
    }

    // cout << find_root(2-1)+1 << "\n";
    // add_edge(2-1, 1);
    // cout << find_root(2-1)+1 << "\n";

    // add_edge(4-1, 1);
    // add_edge(2-1,-1);
    // cout << find_root(4-1) + 1 << "\n";

    //add_edge(0,1);

    for (int d: darr) {
        active[d] = !active[d];
        int u,v;
        tie(u,v) = el[d];
        if (dep[u] < dep[v]) swap(u,v);
        int rtV = find_root(v);
        if (active[d]) {
         //   cout << "adding " << u+1 << " " << v+1 << "\n";
           // cout << num_edges(5-1) << "\n";
          //  int rtU = find_root(u);
          //  cout << rtU+1 << " " << rtV+1 << "\n";
            a[rtV] = a[u] = a[rtV] + a[u] - c[u];
            //a[u] = 0;
            add_edge(u, 1);
        }
        if (!active[d]) {
            a[u] = c[u] = a[rtV];
            //cout << "removing " << u+1 << " " << v+1 << "\n";
            add_edge(u, -1);
        }
    }
    

    cout << a[C] << "\n";


    return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 13688 KB Output is correct
2 Correct 12 ms 13688 KB Output is correct
3 Correct 12 ms 13688 KB Output is correct
4 Correct 12 ms 13688 KB Output is correct
5 Correct 12 ms 13688 KB Output is correct
6 Correct 14 ms 13688 KB Output is correct
7 Correct 38 ms 14328 KB Output is correct
8 Correct 39 ms 14328 KB Output is correct
9 Correct 38 ms 14328 KB Output is correct
10 Correct 477 ms 19052 KB Output is correct
11 Correct 510 ms 18928 KB Output is correct
12 Correct 512 ms 21612 KB Output is correct
13 Correct 210 ms 19180 KB Output is correct
14 Correct 296 ms 18544 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 226 ms 21356 KB Output is correct
2 Correct 220 ms 20204 KB Output is correct
3 Correct 210 ms 22636 KB Output is correct
4 Correct 197 ms 21976 KB Output is correct

Subtask #3
0 / 10.0

# Verdict Execution time Memory Grader output
1 Incorrect 13 ms 13688 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 584 ms 23436 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #5
0 / 40.0

# Verdict Execution time Memory Grader output
1 Incorrect 13 ms 13688 KB Output isn't correct
2 Halted 0 ms 0 KB -