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Submission #762082

# Submission time Handle Problem Language Result Execution time Memory
762082 2023-06-20T18:39:59 Z hyakup Cat in a tree (BOI17_catinatree) C++17
100 / 100
 269 ms 37408 KB 
#include <bits/stdc++.h>
using namespace std;
 
const int maxn = 2e5 + 10;
vector<int> adj[maxn];
int nivel[maxn], nivelCentroid[maxn], sub[maxn], distMin[maxn], dist[20][maxn], paiCentroid[maxn];
bool removed[maxn];
int n, d; 
vector<int> vert;
 
void dfsInit( int cur, int pai ){
    sub[cur] = 1;
    for( int viz : adj[cur] ){
        if( viz == pai || removed[viz] ) continue;
        dfsInit( viz, cur );
        sub[cur] += sub[viz];
    }
}
 
int findCen( int cur, int pai, int sz ){
    for( int viz : adj[cur] ){
        if( viz == pai || removed[viz] ) continue;
        if( sub[viz] > sz/2 ) return findCen( viz, cur, sz );
    }
    return cur;
}
 
void dfs( int cur, int pai, int nivel ){
    for( int viz : adj[cur] ){
        if( viz == pai || removed[viz] ) continue;
        dist[nivel][viz] = dist[nivel][cur] + 1;
        dfs( viz, cur, nivel );
    }
}
 
void decompose( int node, int pai, int nivel ){
    dfsInit( node, node );
    int cen = findCen( node, node, sub[node] );
 
    paiCentroid[cen] = pai;
    nivelCentroid[cen] = nivel;
    dfs( cen, cen, nivel );
    removed[cen] = true;
 
    for( int viz : adj[cen] ) if( !removed[viz] ) decompose( viz, cen, nivel + 1 );
}
 
void update( int x ){
    int cur = x;
    while( cur != -1 ){
        distMin[cur] = min( distMin[cur], dist[nivelCentroid[cur]][x] );
        cur = paiCentroid[cur];
    }
}
 
int query( int x ){
    int resp = maxn;
    int cur = x;
    while( cur != -1 ){
        resp = min( resp, dist[nivelCentroid[cur]][x] + distMin[cur] );
        cur = paiCentroid[cur];
    }
    return resp;
}
 
void dfs2( int cur, int pai ){
    for( int viz : adj[cur] ){
        if( viz == pai ) continue;
        nivel[viz] = nivel[cur] + 1;
        dfs2( viz, cur );
    }
}
 
int achaPonta( int source ){
    nivel[source] = 0;
    dfs2( source, source );
    pair< int, int > resp( -1, -1 );
    for( int i = 0; i < n; i++ ){ resp = max( resp, make_pair( nivel[i], i ) ); }
    return resp.second;
}
 
bool cmp( int a, int b ){ return nivel[a] > nivel[b]; }
 
int solve( int node ){
    nivel[node] = 0;
    dfs2( node, node );
    sort( vert.begin(), vert.end(), cmp );
    int resp = 1;
    update(vert[0]);
    for( int i = 1; i < n; i++ ){
        if( query( vert[i] ) >= d ){
            resp++;
            update(vert[i]);
        }
    }
    return resp;
}

void init( int n ){
    for( int i = 0; i < n; i++ ){
        distMin[i] = maxn;
        vert.push_back(i);
    }
}
 
int main(){
    cin >> n >> d;
    init(n);
    for( int i = 1; i < n; i++ ){
        int x; cin >> x;
        adj[i].push_back(x);
        adj[x].push_back(i);
    }
    decompose( 0, -1, 0 );
    cout << solve(achaPonta(0));
}

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 2 ms 4948 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 2 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct
11 Correct 2 ms 4948 KB Output is correct
12 Correct 2 ms 4948 KB Output is correct
13 Correct 2 ms 4948 KB Output is correct
14 Correct 2 ms 4948 KB Output is correct
15 Correct 2 ms 4948 KB Output is correct
16 Correct 2 ms 4948 KB Output is correct
17 Correct 2 ms 4948 KB Output is correct
18 Correct 2 ms 4948 KB Output is correct
19 Correct 3 ms 4948 KB Output is correct
20 Correct 2 ms 4948 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 2 ms 4948 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 2 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct
11 Correct 2 ms 4948 KB Output is correct
12 Correct 2 ms 4948 KB Output is correct
13 Correct 2 ms 4948 KB Output is correct
14 Correct 2 ms 4948 KB Output is correct
15 Correct 2 ms 4948 KB Output is correct
16 Correct 2 ms 4948 KB Output is correct
17 Correct 2 ms 4948 KB Output is correct
18 Correct 2 ms 4948 KB Output is correct
19 Correct 3 ms 4948 KB Output is correct
20 Correct 2 ms 4948 KB Output is correct
21 Correct 3 ms 5332 KB Output is correct
22 Correct 3 ms 5076 KB Output is correct
23 Correct 3 ms 5076 KB Output is correct
24 Correct 3 ms 5076 KB Output is correct
25 Correct 3 ms 5076 KB Output is correct
26 Correct 3 ms 5076 KB Output is correct
27 Correct 3 ms 5076 KB Output is correct
28 Correct 3 ms 5204 KB Output is correct
29 Correct 3 ms 5204 KB Output is correct
30 Correct 3 ms 5204 KB Output is correct
31 Correct 3 ms 5204 KB Output is correct
32 Correct 3 ms 5076 KB Output is correct
33 Correct 3 ms 5076 KB Output is correct
34 Correct 3 ms 5076 KB Output is correct
35 Correct 3 ms 5076 KB Output is correct
36 Correct 3 ms 5076 KB Output is correct
37 Correct 3 ms 5204 KB Output is correct
38 Correct 3 ms 5204 KB Output is correct
39 Correct 3 ms 5204 KB Output is correct
40 Correct 3 ms 5332 KB Output is correct

Subtask #3
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 4948 KB Output is correct
2 Correct 3 ms 4948 KB Output is correct
3 Correct 2 ms 4948 KB Output is correct
4 Correct 2 ms 4948 KB Output is correct
5 Correct 3 ms 4948 KB Output is correct
6 Correct 2 ms 4948 KB Output is correct
7 Correct 3 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 2 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct
11 Correct 2 ms 4948 KB Output is correct
12 Correct 2 ms 4948 KB Output is correct
13 Correct 2 ms 4948 KB Output is correct
14 Correct 2 ms 4948 KB Output is correct
15 Correct 2 ms 4948 KB Output is correct
16 Correct 2 ms 4948 KB Output is correct
17 Correct 2 ms 4948 KB Output is correct
18 Correct 2 ms 4948 KB Output is correct
19 Correct 3 ms 4948 KB Output is correct
20 Correct 2 ms 4948 KB Output is correct
21 Correct 3 ms 5332 KB Output is correct
22 Correct 3 ms 5076 KB Output is correct
23 Correct 3 ms 5076 KB Output is correct
24 Correct 3 ms 5076 KB Output is correct
25 Correct 3 ms 5076 KB Output is correct
26 Correct 3 ms 5076 KB Output is correct
27 Correct 3 ms 5076 KB Output is correct
28 Correct 3 ms 5204 KB Output is correct
29 Correct 3 ms 5204 KB Output is correct
30 Correct 3 ms 5204 KB Output is correct
31 Correct 3 ms 5204 KB Output is correct
32 Correct 3 ms 5076 KB Output is correct
33 Correct 3 ms 5076 KB Output is correct
34 Correct 3 ms 5076 KB Output is correct
35 Correct 3 ms 5076 KB Output is correct
36 Correct 3 ms 5076 KB Output is correct
37 Correct 3 ms 5204 KB Output is correct
38 Correct 3 ms 5204 KB Output is correct
39 Correct 3 ms 5204 KB Output is correct
40 Correct 3 ms 5332 KB Output is correct
41 Correct 85 ms 18144 KB Output is correct
42 Correct 99 ms 15732 KB Output is correct
43 Correct 86 ms 15668 KB Output is correct
44 Correct 99 ms 15708 KB Output is correct
45 Correct 83 ms 15572 KB Output is correct
46 Correct 231 ms 26232 KB Output is correct
47 Correct 235 ms 26648 KB Output is correct
48 Correct 257 ms 27188 KB Output is correct
49 Correct 241 ms 26560 KB Output is correct
50 Correct 58 ms 14768 KB Output is correct
51 Correct 49 ms 14984 KB Output is correct
52 Correct 54 ms 14676 KB Output is correct
53 Correct 141 ms 24212 KB Output is correct
54 Correct 141 ms 24256 KB Output is correct
55 Correct 139 ms 24148 KB Output is correct
56 Correct 4 ms 5332 KB Output is correct
57 Correct 18 ms 9020 KB Output is correct
58 Correct 88 ms 23928 KB Output is correct
59 Correct 269 ms 37408 KB Output is correct
60 Correct 87 ms 18548 KB Output is correct
61 Correct 133 ms 21516 KB Output is correct