oj.uz

Submission #903487

# Submission time Handle Problem Language Result Execution time Memory
903487 2024-01-11T08:06:59 Z GrindMachine Synchronization (JOI13_synchronization) C++17
100 / 100
 1591 ms 30696 KB 
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(x) 42
#endif

/*

refs:
https://github.com/mostafa-saad/MyCompetitiveProgramming/blob/master/Olympiad/JOI/JOIOC-13-synchronization.txt

*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

template<typename T>
struct fenwick {
    int siz;
    vector<T> tree;

    fenwick() {

    }

    fenwick(int n) {
        siz = n;
        tree = vector<T>(n + 1);
    }

    int lsb(int x) {
        return x & -x;
    }

    void build(vector<T> &a, int n) {
        for (int i = 1; i <= n; ++i) {
            int par = i + lsb(i);
            tree[i] += a[i];

            if (par <= siz) {
                tree[par] += tree[i];
            }
        }
    }

    void pupd(int i, T v) {
        while (i <= siz) {
            tree[i] += v;
            i += lsb(i);
        }
    }

    T sum(int i) {
        T res = 0;

        while (i) {
            res += tree[i];
            i -= lsb(i);
        }

        return res;
    }

    T query(int l, int r) {
        if (l > r) return 0;
        T res = sum(r) - sum(l - 1);
        return res;
    }
};

vector<pll> adj[N];

struct lca_algo {
    // LCA template (for graphs with 1-based indexing)
 
    int LOG = 1;
    vector<int> depth;
    vector<vector<int>> up;
    vector<int> tin, tout;
    vector<int> edge_node;
    int timer = 1;
 
    lca_algo() {
 
    }
 
    lca_algo(int n) {
        lca_init(n);
    }
 
    void lca_init(int n) {
        while ((1 << LOG) < n) LOG++;
        up = vector<vector<int>>(n + 1, vector<int>(LOG, 1));
        depth = vector<int>(n + 1);
        tin = vector<int>(n + 1);
        tout = vector<int>(n + 1);
        edge_node = vector<int>(n + 1);
        lca_dfs(1, -1);
    }
 
    void lca_dfs(int node, int par) {
        tin[node] = timer++;
 
        for(auto [child,id] : adj[node]) {
            if (child == par) conts;
 
            up[child][0] = node;
            rep1(j, LOG - 1) {
                up[child][j] = up[up[child][j - 1]][j - 1];
            }
 
            depth[child] = depth[node] + 1;
            edge_node[id] = child;

            lca_dfs(child, node);
        }
 
        tout[node] = timer-1;
    }
 
    int lift(int u, int k) {
        rep(j, LOG) {
            if (k & (1 << j)) {
                u = up[u][j];
            }
        }
 
        return u;
    }
 
    int query(int u, int v) {
        if (depth[u] < depth[v]) swap(u, v);
        int k = depth[u] - depth[v];
        u = lift(u, k);
 
        if (u == v) return u;
 
        rev(j, LOG - 1, 0) {
            if (up[u][j] != up[v][j]) {
                u = up[u][j];
                v = up[v][j];
            }
        }
 
        u = up[u][0];
        return u;
    }
 
    int get_dis(int u, int v) {
        int lca = query(u, v);
        return depth[u] + depth[v] - 2 * depth[lca];
    }
 
    bool is_ances(int u, int v){
        return tin[u] <= tin[v] and tout[u] >= tout[v];
    }
};

void solve(int test_case)
{
    ll n,m,q; cin >> n >> m >> q;
    vector<pll> edges(n+5);

    rep1(i,n-1){
        ll u,v; cin >> u >> v;
        adj[u].pb({v,i}), adj[v].pb({u,i});
        edges[i] = {u,v};
    }

    vector<ll> a(n+5);
    rep1(i,n) a[i] = 1;

    lca_algo LCA(n);
    fenwick<ll> fenw(n+5);

    auto edge_change = [&](ll id, ll val){
        ll u = LCA.edge_node[id];
        fenw.pupd(LCA.tin[u],val);
        fenw.pupd(LCA.tout[u]+1,-val);
    };

    auto path_sum = [&](ll u, ll v){
        assert(LCA.is_ances(u,v));
        return fenw.sum(LCA.tin[v])-fenw.sum(LCA.tin[u]);
    };

    auto find_cc = [&](ll u){
        ll l = 0, r = LCA.depth[u];
        ll mx_ances = -1;

        while(l <= r){
            ll mid = (l+r) >> 1;
            ll ances = LCA.lift(u,mid);
            ll len = LCA.depth[u]-LCA.depth[ances];
            ll sum = path_sum(ances,u);

            if(sum == len){
                mx_ances = ances;
                l = mid+1;
            } 
            else{
                r = mid-1;
            }
        }

        assert(mx_ances != -1);
        return mx_ances;
    };

    vector<bool> active(n+5);
    vector<ll> edge_sub(n+5);

    while(m--){
        ll id; cin >> id;
        auto [u,v] = edges[id];
        ll pu = find_cc(u), pv = find_cc(v);

        if(!active[id]){
            active[id] = 1;
            ll new_val = a[pu]+a[pv]-edge_sub[id];
            edge_sub[id] = 0;
            edge_change(id,1);
            pu = find_cc(u);
            a[pu] = new_val;
        }
        else{
            active[id] = 0;
            edge_sub[id] = a[pu];
            edge_change(id,-1);
            ll pu_new = find_cc(u), pv_new = find_cc(v);
            a[pu_new] = a[pv_new] = a[pu];
        }
    }

    while(q--){
        ll u; cin >> u;
        ll pu = find_cc(u);
        ll ans = a[pu];
        cout << ans << endl;
    }
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;

    rep1(i, t) {
        solve(i);
    }

    return 0;
}

Subtask #1
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2652 KB Output is correct
2 Correct 1 ms 2652 KB Output is correct
3 Correct 1 ms 2648 KB Output is correct
4 Correct 1 ms 2808 KB Output is correct
5 Correct 1 ms 2648 KB Output is correct
6 Correct 2 ms 2904 KB Output is correct
7 Correct 24 ms 4700 KB Output is correct
8 Correct 20 ms 4700 KB Output is correct
9 Correct 21 ms 4700 KB Output is correct
10 Correct 461 ms 25924 KB Output is correct
11 Correct 394 ms 25728 KB Output is correct
12 Correct 1591 ms 29896 KB Output is correct
13 Correct 175 ms 25076 KB Output is correct
14 Correct 300 ms 25304 KB Output is correct

Subtask #2
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 426 ms 25944 KB Output is correct
2 Correct 375 ms 26896 KB Output is correct
3 Correct 454 ms 29340 KB Output is correct
4 Correct 385 ms 29412 KB Output is correct

Subtask #3
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2648 KB Output is correct
2 Correct 1 ms 2652 KB Output is correct
3 Correct 1 ms 2652 KB Output is correct
4 Correct 1 ms 2652 KB Output is correct
5 Correct 1 ms 2652 KB Output is correct
6 Correct 5 ms 3004 KB Output is correct
7 Correct 60 ms 5204 KB Output is correct
8 Correct 1591 ms 28924 KB Output is correct
9 Correct 1479 ms 28260 KB Output is correct

Subtask #4
20.0 / 20.0

# Verdict Execution time Memory Grader output
1 Correct 1556 ms 28212 KB Output is correct
2 Correct 546 ms 28324 KB Output is correct
3 Correct 514 ms 28332 KB Output is correct
4 Correct 507 ms 28460 KB Output is correct

Subtask #5
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 2648 KB Output is correct
2 Correct 1 ms 2648 KB Output is correct
3 Correct 1 ms 2652 KB Output is correct
4 Correct 1 ms 2648 KB Output is correct
5 Correct 2 ms 2908 KB Output is correct
6 Correct 23 ms 4988 KB Output is correct
7 Correct 469 ms 26716 KB Output is correct
8 Correct 1463 ms 30696 KB Output is correct
9 Correct 142 ms 26172 KB Output is correct
10 Correct 300 ms 26632 KB Output is correct
11 Correct 530 ms 28616 KB Output is correct
12 Correct 464 ms 28624 KB Output is correct
13 Correct 510 ms 30376 KB Output is correct