Submission #1281733

#	Time	Username	Problem	Language	Result	Execution time	Memory
1281733		baotoan655	Synchronization (JOI13_synchronization)	C++20	100 / 100	226 ms	21936 KiB

synchronization

#include <bits/stdc++.h>
#define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
using namespace std;

const int N = 1e5 + 5, LG = 17;
int n, m, q;
vector<int> g[N];
int up[N][LG], in[N], out[N], tim;
pair<int, int> ed[N];
int bit[N];
void upd(int i, int val) {
    for(++i; i < N; i += i & -i) bit[i] += val;
}
void upd(int l, int r, int val) {
    if(l > r) return;
    upd(l, val);
    upd(r + 1, -val);
}
int get(int i) {
    int res = 0;
    for(++i; i > 0; i -= i & -i) res += bit[i];
    return res;
}
void dfs(int u, int p) {
    in[u] = ++tim;
    for(int v : g[u]) if(v != p) {
        up[v][0] = u;
        for(int i = 1; i < LG; ++i) up[v][i] = up[up[v][i - 1]][i - 1];
        dfs(v, u);
    }
    out[u] = tim;
}
int root(int u) {
    for(int i = LG - 1; i >= 0; --i) {
        if(get(in[up[u][i]]) == get(in[u])) u = up[u][i];
    }
    return u;
}
bool vs[N];
int ans[N], lst[N];
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);

    file("A") else file("task");
    cin >> n >> m >> q;
    for(int i = 1, u, v; i < n; ++i) {
        cin >> u >> v;
        ed[i] = make_pair(u, v);
        g[u].emplace_back(v);
        g[v].emplace_back(u);
    }
    dfs(1, 0);
    for(int i = 1; i <= n; ++i) {
        upd(in[i], out[i], 1);
        ans[i] = 1;\
    }
    for(int _ = 1; _ <= m; ++_) {
        int x;
        cin >> x;
        auto [u, v] = ed[x];
        if(up[v][0] != u) swap(u, v);
        if(!vs[x]) {
            ans[root(u)] += ans[v] - lst[v];
            upd(in[v], out[v], -1);
        } else {
            ans[v] = lst[v] = ans[root(u)];
            upd(in[v], out[v], 1);
        }
        vs[x] ^= 1;
    }
    for(int i = 1; i <= q; ++i) {
        int x;
        cin >> x;
        cout << ans[root(x)] << '\n';
    }
    return 0;
}

Compilation message (stderr)

synchronization.cpp: In function 'int main()':
synchronization.cpp:2:58: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    2 | #define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
synchronization.cpp:45:5: note: in expansion of macro 'file'
   45 |     file("A") else file("task");
      |     ^~~~
synchronization.cpp:2:91: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    2 | #define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                                                    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
synchronization.cpp:45:5: note: in expansion of macro 'file'
   45 |     file("A") else file("task");
      |     ^~~~
synchronization.cpp:2:58: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    2 | #define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
synchronization.cpp:45:20: note: in expansion of macro 'file'
   45 |     file("A") else file("task");
      |                    ^~~~
synchronization.cpp:2:91: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    2 | #define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
      |                                                                                    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
synchronization.cpp:45:20: note: in expansion of macro 'file'
   45 |     file("A") else file("task");
      |                    ^~~~

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