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Submission #821327

# Submission time Handle Problem Language Result Execution time Memory
821327 2023-08-11T09:08:49 Z PanosPask Synchronization (JOI13_synchronization) C++14
100 / 100
 237 ms 29228 KB 
#include <bits/stdc++.h>
#define mp make_pair
#define pb push_back

using namespace std;

typedef pair<int, int> pi;

int N, M, Q;
vector<int> tin, par, sz, head, trav;
vector<int> par_edge;
vector<vector<pi>> adj_list;
vector<bool> available;
int counter = 0;

// Information if it is root and total info contained at removal time
vector<int> a, c;

// Set of roots at each heavy path
vector<set<int>> roots;

void decompose(int node, int h)
{
    head[node] = h;
    tin[node] = counter++;
    trav[tin[node]] = node;
    roots[h].insert(tin[node]);
    a[node] = 1;
    c[node] = 0;

    int BigKid = -1, BigV = 0;
    for (auto [neigh, w] : adj_list[node]) {
        if (neigh != par[node] && sz[neigh] > BigV) {
            BigV = sz[neigh];
            BigKid = neigh;
        }
    }

    if (BigKid != -1) {
        decompose(BigKid, h);
    }

    for (auto [neigh,  w] : adj_list[node]) {
        if (neigh != par[node] && neigh != BigKid)
            decompose(neigh, neigh);
    }
}

void init(int node)
{
    sz[node] = 1;

    for (auto [neigh, id] : adj_list[node]) {
        if (neigh != par[node]) {
            par[neigh] = node;
            init(neigh);
            sz[node] += sz[neigh];
        }
        else {
            par_edge[id] = node;
        }
    }
}

int find_root(int v)
{
    while (roots[head[v]].upper_bound(tin[v]) == roots[head[v]].begin())
        v = par[head[v]];

    auto it = roots[head[v]].upper_bound(tin[v]);
    it--;

    return trav[*it];
}

// Insert edge between u and parent
void insert_edge(int u)
{
    int r = find_root(par[u]);

    a[r] = a[r] + a[u] - c[u];
    roots[head[u]].erase(tin[u]);
}

// Remove edge between u and parent
void remove_edge(int u)
{
    int r = find_root(u);
    c[u] = a[r];
    a[u] = a[r];

    roots[head[u]].insert(tin[u]);
}

int main(void)
{
    scanf("%d %d %d", &N, &M, &Q);

    adj_list.resize(N);
    roots.resize(N);
    head.resize(N);
    par_edge.resize(N);
    sz.resize(N);
    par.resize(N);
    tin.resize(N);
    trav.resize(N);
    a.resize(N);
    c.resize(N);
    available.assign(N - 1, false);

    for (int i = 0; i < N - 1; i++) {
        int u, v;
        scanf("%d %d", &u, &v);
        u--; v--;

        adj_list[u].pb(mp(v, i));
        adj_list[v].pb(mp(u, i));
    }

    par[0] = -1;
    init(0);
    decompose(0, 0);

    while (M--) {
        int t;
        scanf("%d", &t);
        t--;

        int u = par_edge[t];
        if (available[t]) {
            remove_edge(u);
        }
        else {
            insert_edge(u);
        }

        available[t] = !available[t];
    }

    while (Q--) {
        int v;
        scanf("%d", &v);
        v--;

        int r = find_root(v);
        printf("%d\n", a[r]);
    }
}

Compilation message

synchronization.cpp: In function 'void decompose(int, int)':
synchronization.cpp:32:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   32 |     for (auto [neigh, w] : adj_list[node]) {
      |               ^
synchronization.cpp:43:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   43 |     for (auto [neigh,  w] : adj_list[node]) {
      |               ^
synchronization.cpp: In function 'void init(int)':
synchronization.cpp:53:15: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   53 |     for (auto [neigh, id] : adj_list[node]) {
      |               ^
synchronization.cpp: In function 'int main()':
synchronization.cpp:97:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   97 |     scanf("%d %d %d", &N, &M, &Q);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
synchronization.cpp:113:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  113 |         scanf("%d %d", &u, &v);
      |         ~~~~~^~~~~~~~~~~~~~~~~
synchronization.cpp:126:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  126 |         scanf("%d", &t);
      |         ~~~~~^~~~~~~~~~
synchronization.cpp:142:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
  142 |         scanf("%d", &v);
      |         ~~~~~^~~~~~~~~~

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 296 KB Output is correct
4 Correct 1 ms 300 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 468 KB Output is correct
7 Correct 9 ms 2260 KB Output is correct
8 Correct 9 ms 2260 KB Output is correct
9 Correct 9 ms 2368 KB Output is correct
10 Correct 162 ms 21212 KB Output is correct
11 Correct 164 ms 21212 KB Output is correct
12 Correct 200 ms 28424 KB Output is correct
13 Correct 118 ms 21012 KB Output is correct
14 Correct 111 ms 20576 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 83 ms 24640 KB Output is correct
2 Correct 70 ms 24344 KB Output is correct
3 Correct 86 ms 27792 KB Output is correct
4 Correct 77 ms 27820 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 1 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 0 ms 212 KB Output is correct
6 Correct 2 ms 568 KB Output is correct
7 Correct 17 ms 3144 KB Output is correct
8 Correct 237 ms 29188 KB Output is correct
9 Correct 205 ms 29144 KB Output is correct

Subtask #4
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 211 ms 29132 KB Output is correct
2 Correct 91 ms 28764 KB Output is correct
3 Correct 93 ms 28932 KB Output is correct
4 Correct 95 ms 29028 KB Output is correct

Subtask #5
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 468 KB Output is correct
6 Correct 11 ms 2356 KB Output is correct
7 Correct 147 ms 22056 KB Output is correct
8 Correct 219 ms 29228 KB Output is correct
9 Correct 95 ms 22036 KB Output is correct
10 Correct 110 ms 21880 KB Output is correct
11 Correct 89 ms 25732 KB Output is correct
12 Correct 86 ms 25760 KB Output is correct
13 Correct 96 ms 28984 KB Output is correct