oj.uz

Submission #529959

# Submission time Handle Problem Language Result Execution time Memory
529959 2022-02-24T06:49:40 Z 79brue Cat in a tree (BOI17_catinatree) C++14
100 / 100
 475 ms 51076 KB 
#include <bits/stdc++.h>

using namespace std;

typedef long long ll;

int n, d;
ll arr[200002];
vector<int> link[200002];

int sz[200002];
bool centroidUsed[200002];
int centroidPar[200002];
vector<int> centroidChild[200002];
int depth[200002];
int par[200002];
int LCADB[200002][22], radius[200002];

void setSize(int x, int par = -1){
    sz[x] = 1;
    for(auto y: link[x]){
        if(y == par || centroidUsed[y]) continue;
        setSize(y, x);
        sz[x] += sz[y];
    }
}

void dfs(int x, int p = -1){
    for(auto y: link[x]){
        if(y == p) continue;
        depth[y] = depth[x] + 1;
        LCADB[y][0] = par[y] = x;
        dfs(y, x);
    }
}

int getLCA(int x, int y){
    if(depth[x] < depth[y]) swap(x, y);
    for(int i=0; i<20; i++) if((depth[x] - depth[y]) & (1<<i)) x = LCADB[x][i];
    if(x==y) return x;
    for(int i=19; i>=0; i--) if(LCADB[x][i] != LCADB[y][i]) x = LCADB[x][i], y = LCADB[y][i];
    return par[x];
}

int dist(int x, int y){
    return depth[x] + depth[y] - depth[getLCA(x, y)] * 2;
}

int findCentroid(int x, int s, int par = -1){
    for(auto y: link[x]){
        if(y == par || centroidUsed[y]) continue;
        if(sz[y] > s/2) return findCentroid(y, s, x);
    }
    return x;
}

int centroidDecomposition(int x){
    setSize(x);
    int c = findCentroid(x, sz[x]);
    centroidUsed[c] = 1;

    for(auto y: link[c]){
        if(centroidUsed[y]) continue;
        int node = centroidDecomposition(y);
        centroidPar[node] = c;
        centroidChild[c].push_back(node);
    }
    return c;
}

bool alreadyUsed(int x){
    int root = x;
    while(root){
        if(dist(root, x) <= radius[root]) return true;
        root = centroidPar[root];
    }
    return false;
}

void mark(int x){
    int root = x;
    while(root){
        radius[root] = max(radius[root], d - dist(root, x) - 1);
        root = centroidPar[root];
    }
}

int ans;

int main(){
    scanf("%d %d", &n, &d);

    for(int i=1; i<n; i++){
        int x, y;
        scanf("%d", &x);
        y=i+1, x++;
        link[x].push_back(y);
        link[y].push_back(x);
    }

    for(int i=1; i<=n; i++) radius[i] = -1;

    dfs(1);
    centroidDecomposition(1);
    for(int d=1; d<20; d++) for(int i=1; i<=n; i++) LCADB[i][d] = LCADB[LCADB[i][d-1]][d-1];

    vector<pair<int, int> > vec;
    for(int i=1; i<=n; i++) vec.push_back(make_pair(depth[i], i));
    sort(vec.rbegin(), vec.rend());

    for(pair<int, int> p: vec){
        int x = p.second;

        if(alreadyUsed(x)) continue;
        ans++;
        mark(x);
    }
    printf("%d", ans);
}

Compilation message

catinatree.cpp: In function 'int main()':
catinatree.cpp:91:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   91 |     scanf("%d %d", &n, &d);
      |     ~~~~~^~~~~~~~~~~~~~~~~
catinatree.cpp:95:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   95 |         scanf("%d", &x);
      |         ~~~~~^~~~~~~~~~

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 9708 KB Output is correct
2 Correct 7 ms 9688 KB Output is correct
3 Correct 6 ms 9676 KB Output is correct
4 Correct 7 ms 9704 KB Output is correct
5 Correct 7 ms 9708 KB Output is correct
6 Correct 5 ms 9676 KB Output is correct
7 Correct 5 ms 9680 KB Output is correct
8 Correct 5 ms 9676 KB Output is correct
9 Correct 6 ms 9676 KB Output is correct
10 Correct 5 ms 9708 KB Output is correct
11 Correct 5 ms 9676 KB Output is correct
12 Correct 7 ms 9696 KB Output is correct
13 Correct 5 ms 9676 KB Output is correct
14 Correct 8 ms 9800 KB Output is correct
15 Correct 6 ms 9676 KB Output is correct
16 Correct 5 ms 9640 KB Output is correct
17 Correct 5 ms 9676 KB Output is correct
18 Correct 6 ms 9676 KB Output is correct
19 Correct 7 ms 9676 KB Output is correct
20 Correct 7 ms 9708 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 9708 KB Output is correct
2 Correct 7 ms 9688 KB Output is correct
3 Correct 6 ms 9676 KB Output is correct
4 Correct 7 ms 9704 KB Output is correct
5 Correct 7 ms 9708 KB Output is correct
6 Correct 5 ms 9676 KB Output is correct
7 Correct 5 ms 9680 KB Output is correct
8 Correct 5 ms 9676 KB Output is correct
9 Correct 6 ms 9676 KB Output is correct
10 Correct 5 ms 9708 KB Output is correct
11 Correct 5 ms 9676 KB Output is correct
12 Correct 7 ms 9696 KB Output is correct
13 Correct 5 ms 9676 KB Output is correct
14 Correct 8 ms 9800 KB Output is correct
15 Correct 6 ms 9676 KB Output is correct
16 Correct 5 ms 9640 KB Output is correct
17 Correct 5 ms 9676 KB Output is correct
18 Correct 6 ms 9676 KB Output is correct
19 Correct 7 ms 9676 KB Output is correct
20 Correct 7 ms 9708 KB Output is correct
21 Correct 7 ms 10092 KB Output is correct
22 Correct 7 ms 9712 KB Output is correct
23 Correct 5 ms 9804 KB Output is correct
24 Correct 5 ms 9708 KB Output is correct
25 Correct 7 ms 9836 KB Output is correct
26 Correct 6 ms 9796 KB Output is correct
27 Correct 6 ms 9804 KB Output is correct
28 Correct 7 ms 9932 KB Output is correct
29 Correct 6 ms 9968 KB Output is correct
30 Correct 6 ms 9932 KB Output is correct
31 Correct 6 ms 9972 KB Output is correct
32 Correct 9 ms 9904 KB Output is correct
33 Correct 6 ms 9932 KB Output is correct
34 Correct 9 ms 9932 KB Output is correct
35 Correct 7 ms 9932 KB Output is correct
36 Correct 6 ms 9932 KB Output is correct
37 Correct 6 ms 9968 KB Output is correct
38 Correct 6 ms 9932 KB Output is correct
39 Correct 7 ms 9932 KB Output is correct
40 Correct 6 ms 10060 KB Output is correct

Subtask #3
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 6 ms 9708 KB Output is correct
2 Correct 7 ms 9688 KB Output is correct
3 Correct 6 ms 9676 KB Output is correct
4 Correct 7 ms 9704 KB Output is correct
5 Correct 7 ms 9708 KB Output is correct
6 Correct 5 ms 9676 KB Output is correct
7 Correct 5 ms 9680 KB Output is correct
8 Correct 5 ms 9676 KB Output is correct
9 Correct 6 ms 9676 KB Output is correct
10 Correct 5 ms 9708 KB Output is correct
11 Correct 5 ms 9676 KB Output is correct
12 Correct 7 ms 9696 KB Output is correct
13 Correct 5 ms 9676 KB Output is correct
14 Correct 8 ms 9800 KB Output is correct
15 Correct 6 ms 9676 KB Output is correct
16 Correct 5 ms 9640 KB Output is correct
17 Correct 5 ms 9676 KB Output is correct
18 Correct 6 ms 9676 KB Output is correct
19 Correct 7 ms 9676 KB Output is correct
20 Correct 7 ms 9708 KB Output is correct
21 Correct 7 ms 10092 KB Output is correct
22 Correct 7 ms 9712 KB Output is correct
23 Correct 5 ms 9804 KB Output is correct
24 Correct 5 ms 9708 KB Output is correct
25 Correct 7 ms 9836 KB Output is correct
26 Correct 6 ms 9796 KB Output is correct
27 Correct 6 ms 9804 KB Output is correct
28 Correct 7 ms 9932 KB Output is correct
29 Correct 6 ms 9968 KB Output is correct
30 Correct 6 ms 9932 KB Output is correct
31 Correct 6 ms 9972 KB Output is correct
32 Correct 9 ms 9904 KB Output is correct
33 Correct 6 ms 9932 KB Output is correct
34 Correct 9 ms 9932 KB Output is correct
35 Correct 7 ms 9932 KB Output is correct
36 Correct 6 ms 9932 KB Output is correct
37 Correct 6 ms 9968 KB Output is correct
38 Correct 6 ms 9932 KB Output is correct
39 Correct 7 ms 9932 KB Output is correct
40 Correct 6 ms 10060 KB Output is correct
41 Correct 158 ms 41884 KB Output is correct
42 Correct 237 ms 26688 KB Output is correct
43 Correct 131 ms 26684 KB Output is correct
44 Correct 163 ms 26796 KB Output is correct
45 Correct 202 ms 26712 KB Output is correct
46 Correct 419 ms 43536 KB Output is correct
47 Correct 440 ms 43656 KB Output is correct
48 Correct 475 ms 43576 KB Output is correct
49 Correct 428 ms 43668 KB Output is correct
50 Correct 107 ms 26052 KB Output is correct
51 Correct 99 ms 26112 KB Output is correct
52 Correct 88 ms 26104 KB Output is correct
53 Correct 211 ms 42292 KB Output is correct
54 Correct 215 ms 42260 KB Output is correct
55 Correct 209 ms 42296 KB Output is correct
56 Correct 7 ms 10188 KB Output is correct
57 Correct 31 ms 15016 KB Output is correct
58 Correct 176 ms 34104 KB Output is correct
59 Correct 437 ms 51076 KB Output is correct
60 Correct 176 ms 43028 KB Output is correct
61 Correct 262 ms 42016 KB Output is correct