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Submission #762083

# Submission time Handle Problem Language Result Execution time Memory
762083 2023-06-20T18:41:10 Z hyakup Cat in a tree (BOI17_catinatree) C++17
100 / 100
 335 ms 37412 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 );
        sub[cur] += sub[viz];
    }
}
 
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 ){
    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;
}
 
int main(){
    cin >> n >> d;
    vert.push_back(0);
    distMin[0] = maxn;
    for( int i = 1; i < n; i++ ){
        vert.push_back(i);
        int x; cin >> x;
        adj[i].push_back(x);
        adj[x].push_back(i);
        distMin[i] = maxn;
    }
    decompose( 0, -1, 0 );
    int resp = 0;
    int x1 = achaPonta(0);
    resp = max( resp, solve(x1) );
    for( int i = 0; i < n; i++ ) distMin[i] = maxn;
    int x2 = achaPonta(x1);
    resp = max( resp, solve(x2) );
    cout << resp;
}

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 2 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 2 ms 4948 KB Output is correct
6 Correct 2 ms 4948 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct
11 Correct 3 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 2 ms 5020 KB Output is correct
14 Correct 2 ms 4948 KB Output is correct
15 Correct 2 ms 4948 KB Output is correct
16 Correct 3 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 2 ms 4948 KB Output is correct
20 Correct 2 ms 5012 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 2 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 2 ms 4948 KB Output is correct
6 Correct 2 ms 4948 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct
11 Correct 3 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 2 ms 5020 KB Output is correct
14 Correct 2 ms 4948 KB Output is correct
15 Correct 2 ms 4948 KB Output is correct
16 Correct 3 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 2 ms 4948 KB Output is correct
20 Correct 2 ms 5012 KB Output is correct
21 Correct 3 ms 5332 KB Output is correct
22 Correct 2 ms 5108 KB Output is correct
23 Correct 3 ms 5076 KB Output is correct
24 Correct 2 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 5168 KB Output is correct
28 Correct 4 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 4 ms 5204 KB Output is correct
40 Correct 4 ms 5332 KB Output is correct

Subtask #3
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4948 KB Output is correct
2 Correct 2 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 2 ms 4948 KB Output is correct
6 Correct 2 ms 4948 KB Output is correct
7 Correct 2 ms 4948 KB Output is correct
8 Correct 2 ms 4948 KB Output is correct
9 Correct 3 ms 4948 KB Output is correct
10 Correct 2 ms 4948 KB Output is correct
11 Correct 3 ms 4948 KB Output is correct
12 Correct 3 ms 4948 KB Output is correct
13 Correct 2 ms 5020 KB Output is correct
14 Correct 2 ms 4948 KB Output is correct
15 Correct 2 ms 4948 KB Output is correct
16 Correct 3 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 2 ms 4948 KB Output is correct
20 Correct 2 ms 5012 KB Output is correct
21 Correct 3 ms 5332 KB Output is correct
22 Correct 2 ms 5108 KB Output is correct
23 Correct 3 ms 5076 KB Output is correct
24 Correct 2 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 5168 KB Output is correct
28 Correct 4 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 4 ms 5204 KB Output is correct
40 Correct 4 ms 5332 KB Output is correct
41 Correct 101 ms 18092 KB Output is correct
42 Correct 116 ms 15720 KB Output is correct
43 Correct 114 ms 15688 KB Output is correct
44 Correct 99 ms 15660 KB Output is correct
45 Correct 101 ms 15552 KB Output is correct
46 Correct 290 ms 26300 KB Output is correct
47 Correct 291 ms 26708 KB Output is correct
48 Correct 335 ms 26804 KB Output is correct
49 Correct 296 ms 26588 KB Output is correct
50 Correct 59 ms 14676 KB Output is correct
51 Correct 60 ms 14956 KB Output is correct
52 Correct 59 ms 14640 KB Output is correct
53 Correct 194 ms 24192 KB Output is correct
54 Correct 202 ms 24260 KB Output is correct
55 Correct 191 ms 24256 KB Output is correct
56 Correct 4 ms 5332 KB Output is correct
57 Correct 18 ms 8916 KB Output is correct
58 Correct 94 ms 23912 KB Output is correct
59 Correct 303 ms 37412 KB Output is correct
60 Correct 108 ms 18536 KB Output is correct
61 Correct 206 ms 21560 KB Output is correct