Submission #1258603

#	Time	Username	Problem	Language	Result	Execution time	Memory
1258603		CrabCNH	Synchronization (JOI13_synchronization)	C++20	100 / 100	325 ms	35108 KiB

synchronization

#include <bits/stdc++.h>

#define task     "BriantheCrab"

#define int    long long
#define pii    pair <int, int>
#define fi     first
#define se     second
#define szf    sizeof
#define sz(s)  (int)((s).size())
#define all(v) (v).begin(), (v).end()

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

using namespace std;

template <class T> void minimize (T &t, T f) {if (t > f) t = f;}
template <class T> void maximize (T &t, T f) {if (t < f) t = f;}

const int maxN = 2e5 + 5;
const int inf = 1e18 + 7;
const int mod = 1e9 + 7;
const int LOG = 20;

// khong tu code thi khong kha len duoc dau
// biet sol roi thi tu lam not di

struct Fenwick {
    vector <int> bit;
    int n;
    
    inline void init () {
        bit.resize (n + 2, 0);
    }
    
    inline void upd (int id, int val) {
        for (; id < n; id += id & (-id)) {
            bit[id] += val;
        }
    }
    
    inline int get (int id) {
        int res = 0;
        for (; id; id -= id & (-id)) {
            res += bit[id];
        }
        return res;
    }
};

int n, m, q;
int res[maxN], lst[maxN], up[maxN][LOG], h[maxN];
int tIn[maxN], tOut[maxN];
int timer = 0;
vector <pii> ed;
vector <int> adj[maxN];
bool merged[maxN];
Fenwick T;

void dfs (int u, int p) {
    up[u][0] = p;
    tIn[u] = ++timer;
    for (int j = 1; j < LOG; j ++) {
        up[u][j] = up[up[u][j - 1]][j - 1];
    }
    for (auto v : adj[u]) {
        if (v == p) {
            continue;
        }
        h[v] = h[u] + 1;
        dfs (v, u);
    }
    tOut[u] = timer;
}

inline int jump (int u) {
    for (int j = LOG - 1; j >= 0; j --) {
        if (T.get (tIn[up[u][j]]) == T.get (tIn[u])) {
            u = up[u][j];
        }
    }
    return u;
}

inline void print () {
    cout << "print\n";
    for (int i = 1; i <= n; i ++) {
        cout << T.get (tIn[i]) << ' ';
    }
    cout << '\n';
}

void solve () {
    cin >> n >> m >> q;
    for (int i = 1; i <= n - 1; i ++) {
        int u, v;
        cin >> u >> v;
        adj[u].push_back (v);
        adj[v].push_back (u);
        ed.push_back ({u, v});
    }
    dfs (1, 1);
    T.n = timer + 2;
    T.init ();
    for (int i = 1; i <= n; i ++) {
        res[i] = 1;
        T.upd (tIn[i], 1);
        T.upd (tOut[i] + 1, -1);
    }
    //print ();
    for (int i = 1; i <= m; i ++) {
        int x;
        cin >> x;
        auto [u, v] = ed[x - 1];
        if (h[u] > h[v]) {
            swap (u, v);
        }
        if (merged[x] == 0) {
            //cout << u << ' ' << v << ' ' << jump (u) << '\n';
            res[jump (u)] += res[v] - lst[v];
            T.upd (tIn[v], -1);
            T.upd (tOut[v] + 1, 1);
            //cout << tIn[i] << ' ' << tOut[i] << '\n';
            merged[x] = 1;
        }
        else {
            res[v] = lst[v] = res[jump (u)];
            T.upd (tIn[v], 1);
            T.upd (tOut[v] + 1, -1);
            //cout << tIn[i] << ' ' << tOut[i] << '\n';
            merged[x] = 0; 
        }
        //print ();
    }
    while (q --) {
        int x;
        cin >> x;
        cout << res[jump (x)] << '\n';
    }
    return;
}

signed main () {
    cin.tie (nullptr) -> sync_with_stdio (false);
    if (fopen (task".inp", "r")) {
        freopen (task".inp", "r", stdin);
        freopen (task".out", "w", stdout);
    }
    int t = 1;
    //cin >> t;
    while (t --) {
        solve ();
    } 
    return 0;
}
// thfv

Compilation message (stderr)

synchronization.cpp: In function 'int main()':
synchronization.cpp:148:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  148 |         freopen (task".inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
synchronization.cpp:149:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  149 |         freopen (task".out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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