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Submission #434638

# Submission time Handle Problem Language Result Execution time Memory
434638 2021-06-21T13:39:03 Z rqi Cat in a tree (BOI17_catinatree) C++14
100 / 100
 706 ms 97056 KB 
#include <bits/stdc++.h>
using namespace std;
 
typedef pair<int, int> pi;
typedef vector<int> vi;
typedef vector<pi> vpi;
 
#define mp make_pair
#define f first
#define s second
#define pb push_back
#define lb lower_bound
#define ins insert
 
#define sz(x) (int)(x).size()

const int MOD = 1e9+7;

void ckmin(int& a, int b){
    a = min(a, b);
}
 
const int mx = 200005;
int N, D;
vi adj[mx];
int closest_dist[mx];

bool done[mx];
int sub[mx];

void genSub(int node, int p = -1){
    sub[node] = 1;
    for(auto u: adj[node]){
        if(done[u]) continue;
        if(u == p) continue;
        genSub(u, node);
        sub[node]+=sub[u];
    }
}

int getCen(int node){
    genSub(node);
    int cur = node;
    int p = -1;

    while(true){
        bool flag = 0;
        for(auto u: adj[cur]){
            if(done[u]) continue;
            if(u == p) continue;
            if(sub[u]*2 > sub[node]){
                p = cur;
                cur = u;
                flag = 1;
                break;
            }
        }
        if(!flag) break;
    }
    

    return cur;
}

int centroid_par[mx][20];
int centroid_dist[mx][20];
vpi queries[mx];
int dist[mx];

void genDist(int node, int d = 0, int p = -1){
    dist[node] = d;
    for(auto u: adj[node]){
        if(done[u]) continue;
        if(u == p) continue;
        genDist(u, d+1, node);
    }
}

void genCenPar(int node, int c_par = -1){
    int cen = getCen(node);

    // cout << "node, cen, c_par: " << node << ", " << cen << ", " << c_par << "\n";
   
    centroid_par[cen][0] = cen;
    centroid_par[cen][1] = c_par;
    for(int i = 2; i < 20; i++){
        if(c_par == -1){
            centroid_par[cen][i] = -1;
        }
        else{
            centroid_par[cen][i] = centroid_par[c_par][i-1];
        }
    }

    for(int i = 0; i < 20; i++){
        int CEN = centroid_par[cen][i];
        if(CEN != -1){
            queries[CEN].pb(mp(cen, i));
        }
        
    }

    done[cen] = 1;
    for(auto u: adj[cen]){
        if(!done[u]){
            genCenPar(u, cen);
        }
    }
    done[cen] = 0;

    genDist(cen);
    for(auto u: queries[cen]){
        centroid_dist[u.f][u.s] = dist[u.f];
    }
}

int root_dist[mx];

void genRootDist(int node, int d = 0, int p = -1){
    root_dist[node] = d;
    for(auto u: adj[node]){
        if(u == p) continue;
        genRootDist(u, d+1, node);
    }
}

int getMinDist(int node){
    int res = MOD;
    for(int i = 0; i < 20; i++){
        int cen = centroid_par[node][i];
        if(cen != -1){
            ckmin(res, closest_dist[cen]+centroid_dist[node][i]);
        }
    }
    
    return res;
}

void updateClosest(int node){
    for(int i = 0; i < 20; i++){
        int cen = centroid_par[node][i];
        if(i == 19) assert(cen == -1);
        ckmin(closest_dist[cen], centroid_dist[node][i]);
    }
}

vi all_nodes;

void checkClosest(int node){
    // genRootDist(node);
    // for(auto u: all_nodes){
    //     assert(root_dist[u] >= D);
    // }
    // all_nodes.pb(node);
}

int main(){
    cin.tie(0)->sync_with_stdio(0);

    cin >> N >> D;
    for(int i = 1; i < N; i++){
        int xi;
        cin >> xi;
        adj[xi].pb(i);
        adj[i].pb(xi);
    }

    genCenPar(0);

    for(int i = 0; i < N; i++){
        closest_dist[i] = MOD;
    }

    genRootDist(0, 0);
    vpi order;
    for(int i = 0; i < N; i++){
        order.pb(mp(root_dist[i], i));
    }
    sort(order.rbegin(), order.rend());

    // for(int i = 0; i < N; i++){
    //     for(int j = 0; j < 20; j++){
    //         cout << "cen_par: " << i << " " << j << " " << centroid_par[i][j] << "\n";
    //     }

    //     for(int j = 0; j < 20; j++){
    //         cout << "cen_dist: " << i << " " << j << " " << centroid_dist[i][j] << "\n";
    //     }
    // }

    int ans = 0;
    for(auto u: order){
        int node = u.s;
        int min_dist = getMinDist(node);
        if(min_dist >= D){
            updateClosest(node);
            checkClosest(node);
            // cout << node << "\n";
            ans++;
        }
        
    }

    cout << ans << "\n";
}

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 9676 KB Output is correct
2 Correct 6 ms 9740 KB Output is correct
3 Correct 6 ms 9676 KB Output is correct
4 Correct 6 ms 9640 KB Output is correct
5 Correct 6 ms 9676 KB Output is correct
6 Correct 6 ms 9676 KB Output is correct
7 Correct 6 ms 9636 KB Output is correct
8 Correct 6 ms 9676 KB Output is correct
9 Correct 6 ms 9676 KB Output is correct
10 Correct 6 ms 9676 KB Output is correct
11 Correct 7 ms 9676 KB Output is correct
12 Correct 6 ms 9676 KB Output is correct
13 Correct 8 ms 9640 KB Output is correct
14 Correct 6 ms 9664 KB Output is correct
15 Correct 7 ms 9676 KB Output is correct
16 Correct 6 ms 9708 KB Output is correct
17 Correct 7 ms 9644 KB Output is correct
18 Correct 7 ms 9676 KB Output is correct
19 Correct 6 ms 9676 KB Output is correct
20 Correct 6 ms 9676 KB Output is correct

Subtask #2
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 9676 KB Output is correct
2 Correct 6 ms 9740 KB Output is correct
3 Correct 6 ms 9676 KB Output is correct
4 Correct 6 ms 9640 KB Output is correct
5 Correct 6 ms 9676 KB Output is correct
6 Correct 6 ms 9676 KB Output is correct
7 Correct 6 ms 9636 KB Output is correct
8 Correct 6 ms 9676 KB Output is correct
9 Correct 6 ms 9676 KB Output is correct
10 Correct 6 ms 9676 KB Output is correct
11 Correct 7 ms 9676 KB Output is correct
12 Correct 6 ms 9676 KB Output is correct
13 Correct 8 ms 9640 KB Output is correct
14 Correct 6 ms 9664 KB Output is correct
15 Correct 7 ms 9676 KB Output is correct
16 Correct 6 ms 9708 KB Output is correct
17 Correct 7 ms 9644 KB Output is correct
18 Correct 7 ms 9676 KB Output is correct
19 Correct 6 ms 9676 KB Output is correct
20 Correct 6 ms 9676 KB Output is correct
21 Correct 8 ms 10316 KB Output is correct
22 Correct 7 ms 9844 KB Output is correct
23 Correct 7 ms 9804 KB Output is correct
24 Correct 8 ms 9972 KB Output is correct
25 Correct 8 ms 9932 KB Output is correct
26 Correct 7 ms 9932 KB Output is correct
27 Correct 7 ms 9972 KB Output is correct
28 Correct 8 ms 10188 KB Output is correct
29 Correct 8 ms 10224 KB Output is correct
30 Correct 8 ms 10188 KB Output is correct
31 Correct 8 ms 10108 KB Output is correct
32 Correct 7 ms 10188 KB Output is correct
33 Correct 8 ms 10132 KB Output is correct
34 Correct 7 ms 10060 KB Output is correct
35 Correct 7 ms 10108 KB Output is correct
36 Correct 7 ms 10100 KB Output is correct
37 Correct 8 ms 10188 KB Output is correct
38 Correct 8 ms 10228 KB Output is correct
39 Correct 8 ms 10308 KB Output is correct
40 Correct 10 ms 10316 KB Output is correct

Subtask #3
49.0 / 49.0

# Verdict Execution time Memory Grader output
1 Correct 7 ms 9676 KB Output is correct
2 Correct 6 ms 9740 KB Output is correct
3 Correct 6 ms 9676 KB Output is correct
4 Correct 6 ms 9640 KB Output is correct
5 Correct 6 ms 9676 KB Output is correct
6 Correct 6 ms 9676 KB Output is correct
7 Correct 6 ms 9636 KB Output is correct
8 Correct 6 ms 9676 KB Output is correct
9 Correct 6 ms 9676 KB Output is correct
10 Correct 6 ms 9676 KB Output is correct
11 Correct 7 ms 9676 KB Output is correct
12 Correct 6 ms 9676 KB Output is correct
13 Correct 8 ms 9640 KB Output is correct
14 Correct 6 ms 9664 KB Output is correct
15 Correct 7 ms 9676 KB Output is correct
16 Correct 6 ms 9708 KB Output is correct
17 Correct 7 ms 9644 KB Output is correct
18 Correct 7 ms 9676 KB Output is correct
19 Correct 6 ms 9676 KB Output is correct
20 Correct 6 ms 9676 KB Output is correct
21 Correct 8 ms 10316 KB Output is correct
22 Correct 7 ms 9844 KB Output is correct
23 Correct 7 ms 9804 KB Output is correct
24 Correct 8 ms 9972 KB Output is correct
25 Correct 8 ms 9932 KB Output is correct
26 Correct 7 ms 9932 KB Output is correct
27 Correct 7 ms 9972 KB Output is correct
28 Correct 8 ms 10188 KB Output is correct
29 Correct 8 ms 10224 KB Output is correct
30 Correct 8 ms 10188 KB Output is correct
31 Correct 8 ms 10108 KB Output is correct
32 Correct 7 ms 10188 KB Output is correct
33 Correct 8 ms 10132 KB Output is correct
34 Correct 7 ms 10060 KB Output is correct
35 Correct 7 ms 10108 KB Output is correct
36 Correct 7 ms 10100 KB Output is correct
37 Correct 8 ms 10188 KB Output is correct
38 Correct 8 ms 10228 KB Output is correct
39 Correct 8 ms 10308 KB Output is correct
40 Correct 10 ms 10316 KB Output is correct
41 Correct 179 ms 60652 KB Output is correct
42 Correct 264 ms 42872 KB Output is correct
43 Correct 301 ms 43076 KB Output is correct
44 Correct 279 ms 43184 KB Output is correct
45 Correct 258 ms 42992 KB Output is correct
46 Correct 687 ms 76512 KB Output is correct
47 Correct 696 ms 77856 KB Output is correct
48 Correct 660 ms 77280 KB Output is correct
49 Correct 706 ms 77348 KB Output is correct
50 Correct 178 ms 41012 KB Output is correct
51 Correct 219 ms 41204 KB Output is correct
52 Correct 185 ms 41068 KB Output is correct
53 Correct 456 ms 72876 KB Output is correct
54 Correct 431 ms 72204 KB Output is correct
55 Correct 468 ms 72620 KB Output is correct
56 Correct 9 ms 10700 KB Output is correct
57 Correct 41 ms 19572 KB Output is correct
58 Correct 165 ms 56052 KB Output is correct
59 Correct 542 ms 97056 KB Output is correct
60 Correct 195 ms 62956 KB Output is correct
61 Correct 305 ms 70276 KB Output is correct