Submission #886037

#	Time	Username	Problem	Language	Result	Execution time	Memory
886037		Zero_OP	Synchronization (JOI13_synchronization)	C++14	100 / 100	339 ms	37204 KiB

synchronization

#include<bits/stdc++.h>

using namespace std;

#define range(v) begin(v), end(v)
#define compact(v) v.erase(unique(range(v)), end(v))

template<class T> bool minimize(T& a, T b){
    if(a > b) return a = b, true;
    return false;
}

template<class T> bool maximize(T& a, T b){
    if(a < b) return a = b, true;
    return false;
}

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

const int N = 2e5 + 5;

int n, m, q, tin[N], tout[N], lift[20][N], h[N], res[N], info[N], timerDFS;
vector<int> g[N];
pair<int, int> e[N];
bool actived[N];

void dfsEuler(int u, int e){
    tin[u] = ++timerDFS;
    res[u] = 1;
    for(int v : g[u]) if(v != e){
        h[v] = h[u] + 1;
        lift[0][v] = u;
        for(int i = 1; i <= 17; ++i){
            lift[i][v] = lift[i - 1][lift[i - 1][v]];
        }
        dfsEuler(v, u);
    }
    tout[u] = ++timerDFS;
}

int bit[N];
void update(int id, int val){
    for(; id <= timerDFS; id += id & (-id)){
        bit[id] += val;
    }
}

int query(int id){
    int s = 0;
    for(; id > 0; id -= id & (-id)){
        s += bit[id];
    }
    return s;
}

int binLift(int u){
    for(int i = 17; i >= 0; --i){
        if(h[u] - (1 << i) >= 0){
            int p = lift[i][u];
            if(h[u] - h[p] == query(tin[u]) - query(tin[p])){
                u = lift[i][u];
            }
        }
    }
    return u;
}

void Zero_OP(){
    cin >> n >> m >> q;
    for(int i = 1; i < n; ++i){
        int u, v;
        cin >> u >> v;
        g[u].push_back(v);
        g[v].push_back(u);
        e[i] = {u, v};
    }

    dfsEuler(1, 1);
    for(int i = 1; i < n; ++i){
        if(lift[0][e[i].first] == e[i].second){
            swap(e[i].first, e[i].second);
        }
    }

    while(m--){
        int pos; cin >> pos;

        int u = e[pos].first, v = e[pos].second, upper = binLift(u);

        if(actived[pos]){
            res[v] = info[pos] = res[upper];
            update(tin[v], -1);
            update(tout[v], 1);
        }
        else{
            res[upper] += res[v] - info[pos];
            update(tin[v], 1);
            update(tout[v], -1);
        }

        actived[pos] ^= 1;
    }

    while(q--){
        int u; cin >> u;
        u = binLift(u);
        cout << res[u] << '\n';
    }
}

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

    #define task "antuvu"
    if(fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }

    Zero_OP();

    return 0;
}

Compilation message (stderr)

synchronization.cpp: In function 'int main()':
synchronization.cpp:119:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  119 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
synchronization.cpp:120:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  120 |         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