oj.uz

Submission #747695

# Submission time Handle Problem Language Result Execution time Memory
747695 2023-05-24T13:35:47 Z GrindMachine Cat in a tree (BOI17_catinatree) C++17
100 / 100
 485 ms 45536 KB 
// Om Namah Shivaya

#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) 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

/*



*/

const int MOD = 1e9 + 7;
const int N = 2e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

vector<int> adj[N];

struct lca_algo {
    // LCA template (for graphs with 1-based indexing)

    int LOG = 1;
    vector<int> depth;
    vector<vector<int>> up;

    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));
        depth = vector<int>(n + 1);

        lca_dfs(0, -1);
    }

    void lca_dfs(int node, int par) {
        trav(child, 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;

            lca_dfs(child, node);
        }
    }

    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];
    }
};

vector<int> subsiz(N);
vector<bool> rem(N);
vector<int> par(N);

int get_siz(int u, int p){
    subsiz[u] = 1;
    trav(v,adj[u]){
        if(v == p or rem[v]) conts;
        subsiz[u] += get_siz(v,u);
    }
    return subsiz[u];
}

int get_centroid(int u, int p, int nodes){
    trav(v, adj[u]){
        if(v == p or rem[v]) conts;
        if(subsiz[v] > nodes / 2){
            return get_centroid(v,u,nodes);
        }
    }

    return u;
}

void build(int u, int p){
    int nodes = get_siz(u,-1);
    int centroid = get_centroid(u,-1,nodes);

    par[centroid] = p;
    rem[centroid] = 1;

    trav(v, adj[centroid]){
        if(rem[v]) conts;
        build(v,centroid);
    }
}

void solve(int test_case)
{
    int n,d; cin >> n >> d;
    rep1(i,n){
        int p; cin >> p;
        adj[p].pb(i), adj[i].pb(p);
    }

    lca_algo LCA(n);
    build(0,-1);

    vector<pii> order;
    rep(i,n){
        order.pb({LCA.depth[i],i});
    }

    sort(rall(order));

    vector<int> best(n,inf1);
    int ans = 0;

    for(auto [dep, u] : order){
        // find closest active guy
        // similar to cf xenia and tree
        int mnd = inf1;
        int lca = u;

        while(lca != -1){
            int du = LCA.get_dis(u,lca);
            int d = du + best[lca];
            amin(mnd, d);
            lca = par[lca];
        }

        if(mnd >= d){
            // activate
            ans++;

            lca = u;
            while(lca != -1){
                int du = LCA.get_dis(u,lca);
                amin(best[lca], du);
                lca = par[lca];
            }
        }
    }

    cout << ans << endl;
}

int main()
{
    fastio;

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

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

    return 0;
}

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 6612 KB Output is correct
2 Correct 4 ms 6612 KB Output is correct
3 Correct 3 ms 6612 KB Output is correct
4 Correct 4 ms 6628 KB Output is correct
5 Correct 4 ms 6612 KB Output is correct
6 Correct 3 ms 6612 KB Output is correct
7 Correct 3 ms 6612 KB Output is correct
8 Correct 4 ms 6624 KB Output is correct
9 Correct 4 ms 6512 KB Output is correct
10 Correct 3 ms 6612 KB Output is correct
11 Correct 5 ms 6504 KB Output is correct
12 Correct 4 ms 6628 KB Output is correct
13 Correct 4 ms 6540 KB Output is correct
14 Correct 4 ms 6612 KB Output is correct
15 Correct 4 ms 6536 KB Output is correct
16 Correct 3 ms 6612 KB Output is correct
17 Correct 3 ms 6612 KB Output is correct
18 Correct 3 ms 6612 KB Output is correct
19 Correct 4 ms 6612 KB Output is correct
20 Correct 4 ms 6624 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 6612 KB Output is correct
2 Correct 4 ms 6612 KB Output is correct
3 Correct 3 ms 6612 KB Output is correct
4 Correct 4 ms 6628 KB Output is correct
5 Correct 4 ms 6612 KB Output is correct
6 Correct 3 ms 6612 KB Output is correct
7 Correct 3 ms 6612 KB Output is correct
8 Correct 4 ms 6624 KB Output is correct
9 Correct 4 ms 6512 KB Output is correct
10 Correct 3 ms 6612 KB Output is correct
11 Correct 5 ms 6504 KB Output is correct
12 Correct 4 ms 6628 KB Output is correct
13 Correct 4 ms 6540 KB Output is correct
14 Correct 4 ms 6612 KB Output is correct
15 Correct 4 ms 6536 KB Output is correct
16 Correct 3 ms 6612 KB Output is correct
17 Correct 3 ms 6612 KB Output is correct
18 Correct 3 ms 6612 KB Output is correct
19 Correct 4 ms 6612 KB Output is correct
20 Correct 4 ms 6624 KB Output is correct
21 Correct 5 ms 6868 KB Output is correct
22 Correct 4 ms 6612 KB Output is correct
23 Correct 4 ms 6620 KB Output is correct
24 Correct 4 ms 6612 KB Output is correct
25 Correct 4 ms 6740 KB Output is correct
26 Correct 5 ms 6740 KB Output is correct
27 Correct 4 ms 6644 KB Output is correct
28 Correct 5 ms 6740 KB Output is correct
29 Correct 4 ms 6792 KB Output is correct
30 Correct 5 ms 6756 KB Output is correct
31 Correct 5 ms 6740 KB Output is correct
32 Correct 4 ms 6740 KB Output is correct
33 Correct 4 ms 6788 KB Output is correct
34 Correct 4 ms 6740 KB Output is correct
35 Correct 4 ms 6752 KB Output is correct
36 Correct 5 ms 6740 KB Output is correct
37 Correct 4 ms 6740 KB Output is correct
38 Correct 5 ms 6868 KB Output is correct
39 Correct 5 ms 6880 KB Output is correct
40 Correct 5 ms 6884 KB Output is correct

Subtask #3
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 6612 KB Output is correct
2 Correct 4 ms 6612 KB Output is correct
3 Correct 3 ms 6612 KB Output is correct
4 Correct 4 ms 6628 KB Output is correct
5 Correct 4 ms 6612 KB Output is correct
6 Correct 3 ms 6612 KB Output is correct
7 Correct 3 ms 6612 KB Output is correct
8 Correct 4 ms 6624 KB Output is correct
9 Correct 4 ms 6512 KB Output is correct
10 Correct 3 ms 6612 KB Output is correct
11 Correct 5 ms 6504 KB Output is correct
12 Correct 4 ms 6628 KB Output is correct
13 Correct 4 ms 6540 KB Output is correct
14 Correct 4 ms 6612 KB Output is correct
15 Correct 4 ms 6536 KB Output is correct
16 Correct 3 ms 6612 KB Output is correct
17 Correct 3 ms 6612 KB Output is correct
18 Correct 3 ms 6612 KB Output is correct
19 Correct 4 ms 6612 KB Output is correct
20 Correct 4 ms 6624 KB Output is correct
21 Correct 5 ms 6868 KB Output is correct
22 Correct 4 ms 6612 KB Output is correct
23 Correct 4 ms 6620 KB Output is correct
24 Correct 4 ms 6612 KB Output is correct
25 Correct 4 ms 6740 KB Output is correct
26 Correct 5 ms 6740 KB Output is correct
27 Correct 4 ms 6644 KB Output is correct
28 Correct 5 ms 6740 KB Output is correct
29 Correct 4 ms 6792 KB Output is correct
30 Correct 5 ms 6756 KB Output is correct
31 Correct 5 ms 6740 KB Output is correct
32 Correct 4 ms 6740 KB Output is correct
33 Correct 4 ms 6788 KB Output is correct
34 Correct 4 ms 6740 KB Output is correct
35 Correct 4 ms 6752 KB Output is correct
36 Correct 5 ms 6740 KB Output is correct
37 Correct 4 ms 6740 KB Output is correct
38 Correct 5 ms 6868 KB Output is correct
39 Correct 5 ms 6880 KB Output is correct
40 Correct 5 ms 6884 KB Output is correct
41 Correct 143 ms 35984 KB Output is correct
42 Correct 251 ms 22140 KB Output is correct
43 Correct 178 ms 22120 KB Output is correct
44 Correct 190 ms 22120 KB Output is correct
45 Correct 181 ms 22116 KB Output is correct
46 Correct 470 ms 37676 KB Output is correct
47 Correct 481 ms 37736 KB Output is correct
48 Correct 459 ms 37692 KB Output is correct
49 Correct 485 ms 37728 KB Output is correct
50 Correct 106 ms 22388 KB Output is correct
51 Correct 130 ms 22500 KB Output is correct
52 Correct 117 ms 22380 KB Output is correct
53 Correct 266 ms 38124 KB Output is correct
54 Correct 261 ms 38208 KB Output is correct
55 Correct 265 ms 38208 KB Output is correct
56 Correct 6 ms 7020 KB Output is correct
57 Correct 32 ms 11476 KB Output is correct
58 Correct 181 ms 29020 KB Output is correct
59 Correct 485 ms 45536 KB Output is correct
60 Correct 148 ms 36796 KB Output is correct
61 Correct 267 ms 36012 KB Output is correct