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Submission #868069

# Submission time Handle Problem Language Result Execution time Memory
868069 2023-10-30T11:19:58 Z phong Cat in a tree (BOI17_catinatree) C++17
100 / 100
 284 ms 74708 KB 
#include <bits/stdc++.h>

#define ll long long
const int nmax = 2e5 + 5;
const int mod = 1e9 + 7;
const int lg = 19;
const int M = 1 << 18;
const ll oo = 1e9 + 1;
#define fi first
#define se second
#define pii pair<int, ll>
using namespace std;

int n, d, m = 0;
int h[nmax], idx[nmax], par[nmax], sz[nmax];
int up[nmax][lg + 1], st[nmax * 2], tour[nmax * 2], rmq[nmax * 2][lg + 1];
bool vis[nmax];
vector<int> adj[nmax];

void dfs(int u, int p){
    tour[++m] = u;
    for(auto v : adj[u]){
        if(v == p) continue;
        h[v] = h[u] + 1;
        up[v][0] = u;
        for(int j = 1; j <= lg; ++j) up[v][j] = up[up[v][j - 1]][j - 1];
        dfs(v, u);
        tour[++m] = u;

    }
}


void dfs1(int u, int p){
    sz[u] = 1;
    for(auto v : adj[u]){
        if(vis[v] || v == p) continue;
        dfs1(v, u);
        sz[u] += sz[v];
    }
}
int get(int l, int r){
    if(l > r) swap(l, r);
    int k = __lg(r - l + 1);
    return min(rmq[l][k], rmq[r - (1 << k) + 1][k]);
}
int dist(int u, int v){
    return h[u] + h[v] - 2 * get(st[u], st[v]);
}
int cntw, root;
void dfs2(int u, int p){
    for(auto v : adj[u]){
        if(vis[v] || v == p) continue;
        if(sz[v] > cntw / 2) return dfs2(v, u);
    }
    root = u;
}

int build(int u){
    dfs1(u, -1); cntw = sz[u];
    dfs2(u, -1); vis[root] = 1;
    int dcm = root;
    for(auto v : adj[dcm]){
        if(vis[v]) continue;
        int x = build(v);
        par[x] = dcm;
    }
    return dcm;
}

int dp[nmax], ans = 0;

void update(int u){
    int v = u;
    while(u > 0){
        dp[u] = min(dp[u], dist(u, v));
        u = par[u];
    }
}

void check(int u){
    int ma = oo;
    int v = u;
    while(u > 0){
        ma = min(ma, dist(u, v) + dp[u]);
        u = par[u];
    }
    if(ma >= d){
        update(v);
        ans++;
    }
}
int main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0), cout.tie(0);
    cin >> n >> d;
    for(int i = 2, x; i <= n; ++i){
        cin >> x;
        ++x;
        adj[x].push_back(i);
        adj[i].push_back(x);
    }
    dfs(1, -1);build(1);
    memset(dp, 0x3f, sizeof dp);
    for(int i = 1; i <= n; ++i) idx[i] = i;
    for(int i = m; i >= 1; --i){
        int u = tour[i];
        rmq[i][0] = h[u];
        st[u] = i;
    }
    for(int j = 1; j <= lg; ++j){
        for(int i = 1; i + (1 << j) - 1 <= m; ++i){
            rmq[i][j] = min(rmq[i][j - 1], rmq[i + (1 << (j - 1))][j - 1]);
        }
    }
    sort(idx + 1, idx + 1 + n, [](int a, int b){
         return h[a] > h[b];
         });
    for(int i = 1; i <= n; ++i){
        int x = idx[i];
        check(x);
    }
    cout << ans;

}
/*


*/

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 14940 KB Output is correct
2 Correct 2 ms 14940 KB Output is correct
3 Correct 2 ms 14940 KB Output is correct
4 Correct 2 ms 14940 KB Output is correct
5 Correct 2 ms 14940 KB Output is correct
6 Correct 2 ms 14940 KB Output is correct
7 Correct 2 ms 14940 KB Output is correct
8 Correct 2 ms 14776 KB Output is correct
9 Correct 2 ms 14940 KB Output is correct
10 Correct 2 ms 14940 KB Output is correct
11 Correct 2 ms 14940 KB Output is correct
12 Correct 3 ms 14940 KB Output is correct
13 Correct 2 ms 14940 KB Output is correct
14 Correct 2 ms 14940 KB Output is correct
15 Correct 3 ms 14940 KB Output is correct
16 Correct 3 ms 14776 KB Output is correct
17 Correct 2 ms 14940 KB Output is correct
18 Correct 2 ms 14936 KB Output is correct
19 Correct 2 ms 14940 KB Output is correct
20 Correct 2 ms 14940 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 14940 KB Output is correct
2 Correct 2 ms 14940 KB Output is correct
3 Correct 2 ms 14940 KB Output is correct
4 Correct 2 ms 14940 KB Output is correct
5 Correct 2 ms 14940 KB Output is correct
6 Correct 2 ms 14940 KB Output is correct
7 Correct 2 ms 14940 KB Output is correct
8 Correct 2 ms 14776 KB Output is correct
9 Correct 2 ms 14940 KB Output is correct
10 Correct 2 ms 14940 KB Output is correct
11 Correct 2 ms 14940 KB Output is correct
12 Correct 3 ms 14940 KB Output is correct
13 Correct 2 ms 14940 KB Output is correct
14 Correct 2 ms 14940 KB Output is correct
15 Correct 3 ms 14940 KB Output is correct
16 Correct 3 ms 14776 KB Output is correct
17 Correct 2 ms 14940 KB Output is correct
18 Correct 2 ms 14936 KB Output is correct
19 Correct 2 ms 14940 KB Output is correct
20 Correct 2 ms 14940 KB Output is correct
21 Correct 3 ms 14940 KB Output is correct
22 Correct 3 ms 14940 KB Output is correct
23 Correct 2 ms 14940 KB Output is correct
24 Correct 2 ms 14940 KB Output is correct
25 Correct 3 ms 14940 KB Output is correct
26 Correct 3 ms 15024 KB Output is correct
27 Correct 3 ms 14940 KB Output is correct
28 Correct 3 ms 14940 KB Output is correct
29 Correct 3 ms 14940 KB Output is correct
30 Correct 3 ms 14940 KB Output is correct
31 Correct 3 ms 14940 KB Output is correct
32 Correct 3 ms 14940 KB Output is correct
33 Correct 3 ms 14940 KB Output is correct
34 Correct 3 ms 14940 KB Output is correct
35 Correct 3 ms 14940 KB Output is correct
36 Correct 3 ms 14940 KB Output is correct
37 Correct 3 ms 14940 KB Output is correct
38 Correct 3 ms 14940 KB Output is correct
39 Correct 3 ms 14940 KB Output is correct
40 Correct 3 ms 14940 KB Output is correct

Subtask #3
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 14940 KB Output is correct
2 Correct 2 ms 14940 KB Output is correct
3 Correct 2 ms 14940 KB Output is correct
4 Correct 2 ms 14940 KB Output is correct
5 Correct 2 ms 14940 KB Output is correct
6 Correct 2 ms 14940 KB Output is correct
7 Correct 2 ms 14940 KB Output is correct
8 Correct 2 ms 14776 KB Output is correct
9 Correct 2 ms 14940 KB Output is correct
10 Correct 2 ms 14940 KB Output is correct
11 Correct 2 ms 14940 KB Output is correct
12 Correct 3 ms 14940 KB Output is correct
13 Correct 2 ms 14940 KB Output is correct
14 Correct 2 ms 14940 KB Output is correct
15 Correct 3 ms 14940 KB Output is correct
16 Correct 3 ms 14776 KB Output is correct
17 Correct 2 ms 14940 KB Output is correct
18 Correct 2 ms 14936 KB Output is correct
19 Correct 2 ms 14940 KB Output is correct
20 Correct 2 ms 14940 KB Output is correct
21 Correct 3 ms 14940 KB Output is correct
22 Correct 3 ms 14940 KB Output is correct
23 Correct 2 ms 14940 KB Output is correct
24 Correct 2 ms 14940 KB Output is correct
25 Correct 3 ms 14940 KB Output is correct
26 Correct 3 ms 15024 KB Output is correct
27 Correct 3 ms 14940 KB Output is correct
28 Correct 3 ms 14940 KB Output is correct
29 Correct 3 ms 14940 KB Output is correct
30 Correct 3 ms 14940 KB Output is correct
31 Correct 3 ms 14940 KB Output is correct
32 Correct 3 ms 14940 KB Output is correct
33 Correct 3 ms 14940 KB Output is correct
34 Correct 3 ms 14940 KB Output is correct
35 Correct 3 ms 14940 KB Output is correct
36 Correct 3 ms 14940 KB Output is correct
37 Correct 3 ms 14940 KB Output is correct
38 Correct 3 ms 14940 KB Output is correct
39 Correct 3 ms 14940 KB Output is correct
40 Correct 3 ms 14940 KB Output is correct
41 Correct 116 ms 65228 KB Output is correct
42 Correct 99 ms 43888 KB Output is correct
43 Correct 112 ms 43892 KB Output is correct
44 Correct 79 ms 43860 KB Output is correct
45 Correct 75 ms 43856 KB Output is correct
46 Correct 241 ms 66900 KB Output is correct
47 Correct 241 ms 66900 KB Output is correct
48 Correct 245 ms 66976 KB Output is correct
49 Correct 284 ms 66980 KB Output is correct
50 Correct 56 ms 44116 KB Output is correct
51 Correct 56 ms 44112 KB Output is correct
52 Correct 63 ms 44116 KB Output is correct
53 Correct 192 ms 67416 KB Output is correct
54 Correct 169 ms 67224 KB Output is correct
55 Correct 168 ms 67196 KB Output is correct
56 Correct 5 ms 14936 KB Output is correct
57 Correct 15 ms 23384 KB Output is correct
58 Correct 93 ms 50636 KB Output is correct
59 Correct 209 ms 74708 KB Output is correct
60 Correct 125 ms 66508 KB Output is correct
61 Correct 167 ms 66548 KB Output is correct