Submission #1064014

#	Time	Username	Problem	Language	Result	Execution time	Memory
1064014		Boycl07	Synchronization (JOI13_synchronization)	C++17	100 / 100	222 ms	32548 KiB

synchronization

#include <bits/stdc++.h>
using namespace std;

typedef long long ll;

#define int ll
#define rep(i, n) for(int i = 1; (i) <= (n); ++i)
#define forn(i, l, r) for(int i = (l); i <= (r); ++i)
#define ford(i, r, l) for(int i = (r); i >= (l); --i)
#define FOR(i, n) for(int i = 0; i < (n); ++i)
#define FORD(i, n) for(int i = ((n) - 1); i >= 0; --i)
#define fi first
#define se second
#define pii pair<int, int>
#define pll pair<ll, ll>
#define pb push_back
#define endl "\n"
#define task "FFILL"
#define sz(a) int(a.size())
#define C(x, y) make_pair(x, y)
#define all(a) (a).begin(), (a).end()
#define bit(i, mask) (mask >> i & 1)

template<typename T> bool maximize(T &res, const T &val) { if (res < val){ res = val; return true; }; return false; }
template<typename T> bool minimize(T &res, const T &val) { if (res > val){ res = val; return true; }; return false; }


const int N = 1e5 + 3;
const int LIM = (1 << 16) + 3;
const int INF = 1e9 + 1;
const int LOG = 16;
int n, m, q;
vector<int> g[N];

int timedfs = 0;

pii e[N];

int up[N][LOG + 1], tin[N], tout[N], ans[N], b[N], bit[N];

bool c[N];


void update(int u, int v)
{
    for(; u <= n; u += u & -u) bit[u] += v;
}

int get(int u)
{
    int res = 0;
    for(; u; u -= u & -u) res += bit[u];
    return res;
}

void dfs(int u, int p)
{
    tin[u] = ++timedfs;
    up[u][0] = p;
    forn(i, 1, LOG) up[u][i] = up[up[u][i - 1]][i - 1];

    for(int v : g[u]) if(v != p) dfs(v, u);

    tout[u] = timedfs;
}

int root(int u)
{

    ford(i, LOG, 0) if(get(tin[u]) == get(tin[up[u][i]]))
        u = up[u][i];
    return u;
}

void solve()
{
    cin >> n >> m >> q;
    rep(i, n - 1)
    {
        int u, v;
        cin >> u >> v;
        g[u].pb(v);
        g[v].pb(u);
        e[i] = {u, v};
    }

    dfs(1, 1);
    rep(i, n) update(tin[i], 1), update(tout[i] + 1, -1), ans[i] = 1;

    rep(_, m)
    {
        int idx;
        cin >> idx;
        int u = e[idx].fi, v = e[idx].se;

        if(up[u][0] == v) swap(u, v);

        if(c[v])
        {
            ans[v] = b[v] = ans[root(u)];
            update(tin[v], 1);
            update(tout[v] + 1, -1);
        }
        else
        {
            ans[root(u)] += ans[v] - b[v];
            update(tin[v], -1);
            update(tout[v] + 1, 1);
        }
        c[v] ^= 1;
    }
    rep(_, q)
    {
        int u;
        cin >> u;
        cout << ans[root(u)] << endl;
    }
}

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

    int TC = 1;

    if(fopen("note.inp", "r"))
    {
        freopen("note.inp", "r", stdin);
        freopen("note.out", "w", stdout);
    }


    while(TC--)
    {
        solve();
    }

    return 0;
}

Compilation message (stderr)

synchronization.cpp: In function 'int main()':
synchronization.cpp:129:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  129 |         freopen("note.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
synchronization.cpp:130:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  130 |         freopen("note.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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