oj.uz

Submission #930083

# Submission time Handle Problem Language Result Execution time Memory
930083 2024-02-18T12:49:43 Z Karoot Network (BOI15_net) C++17
100 / 100
 744 ms 128828 KB 
#include <iostream>
#include <cmath>
#include <unordered_map>
#include <map>
#include <set>
#include <queue>
#include <vector>
#include <string>
#include <iomanip>
#include <algorithm>
#include <deque>

#define all(x)  (x).begin(), (x).end()
#define rall(x)  (x).rbegin(), (x).rend()

using namespace std;

typedef long long ll;

ll linf = 1e15+1;

inline void scoobydoobydoo(){
    ios::sync_with_stdio(false);
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);
}

const int MAXN = 5e5+1;
vector<int> adj[MAXN];
vector<pair<int, int> > children[MAXN];
bool isLeaf[MAXN];
int leafSz[MAXN];
double leafCount = 0;
bool skip[MAXN];

int rootTree(int node, int parent){
    leafSz[node] = 0;
    if (adj[node].size() == 1 && node != parent){
        leafCount++;
        leafSz[node]++;
        isLeaf[node] = true;
        if (node != parent)children[parent].push_back({leafSz[node], node});
        return leafSz[node];
    }
    for (auto e : adj[node]){
        if (e != parent)leafSz[node] += rootTree(e, node);
    }
    if (node != parent)children[parent].push_back({leafSz[node], node});
    return leafSz[node];
}

int getCentroid(int node){
    if ((double)children[node][0].first <= (leafCount/2.0)){
        return node;
    }

    return getCentroid(children[node][0].second);
}

vector<int> tempLeaves;

void getLeaves(int node){
    if (isLeaf[node])tempLeaves.push_back(node);
    for (auto p : children[node]){
        getLeaves(p.second);
    }
}

set<int> leaves[MAXN];

int main(){
    scoobydoobydoo();
    int n; cin >> n;
    
    for (int i = 0; i < n-1; i++){
        int a, b; cin >> a >> b;
        a--; b--;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }

    rootTree(0, 0);

    for (int i = 0; i < n; i++)sort(rall(children[i]));
    int nRoot = getCentroid(0);

    for (int i = 0; i < n; i++){
        children[i].clear();
        leafSz[i] = 0;
    }

    rootTree(nRoot, nRoot);


    sort(rall(children[nRoot]));

    int firstOne = -1;

    vector<pair<int, int> > ans;

    set<pair<int, int> > s;

    for (auto p : children[nRoot]){
        tempLeaves.clear();
        getLeaves(p.second);
        for (int x : tempLeaves)leaves[p.second].insert(x);
        s.insert(p);
    }

    int counter = 0;
    while (s.size()){
        //cout << ++counter << endl;
        auto it = s.end();
        it--;
        pair<int, int> p1 = *it;
        if (s.size() == 1){
            for (auto& e : leaves[p1.second]){
                ans.push_back({firstOne, e});
            }
            break;
        }
        it--;
        pair<int, int> p2 = *it;

        //cout << "(" << p1.first << "," << p1.second << ")   " << "(" << p2.first << "," << p2.second << ")  " << endl;

        ans.push_back({*leaves[p1.second].begin(), *leaves[p2.second].begin()});

        if (firstOne == -1)firstOne = *leaves[p1.second].begin();

        leaves[p1.second].erase(leaves[p1.second].begin());
        leaves[p2.second].erase(leaves[p2.second].begin());

        auto itr = s.end();
        itr--;
        s.erase(itr);
        itr = s.end();
        itr--;
        s.erase(itr);
        if (leaves[p1.second].size())s.insert({leaves[p1.second].size(), p1.second});
        if (leaves[p2.second].size())s.insert({leaves[p2.second].size(), p2.second});


    }


    cout << ans.size() << endl;
    for (auto p : ans)cout << p.first+1 << " " << p.second+1 << endl;









    



    return 0;
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:110:9: warning: unused variable 'counter' [-Wunused-variable]
  110 |     int counter = 0;
      |         ^~~~~~~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 50264 KB Output is correct
2 Correct 11 ms 50264 KB Output is correct
3 Correct 11 ms 50288 KB Output is correct
4 Correct 11 ms 50268 KB Output is correct
5 Correct 11 ms 50264 KB Output is correct
6 Correct 10 ms 50268 KB Output is correct
7 Correct 11 ms 50268 KB Output is correct
8 Correct 11 ms 50268 KB Output is correct
9 Correct 11 ms 50308 KB Output is correct
10 Correct 11 ms 50420 KB Output is correct
11 Correct 10 ms 50268 KB Output is correct
12 Correct 10 ms 50264 KB Output is correct
13 Correct 11 ms 50268 KB Output is correct
14 Correct 10 ms 50268 KB Output is correct
15 Correct 11 ms 50268 KB Output is correct
16 Correct 11 ms 50268 KB Output is correct
17 Correct 10 ms 50520 KB Output is correct
18 Correct 10 ms 50268 KB Output is correct
19 Correct 11 ms 50268 KB Output is correct
20 Correct 11 ms 50268 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 50264 KB Output is correct
2 Correct 11 ms 50264 KB Output is correct
3 Correct 11 ms 50288 KB Output is correct
4 Correct 11 ms 50268 KB Output is correct
5 Correct 11 ms 50264 KB Output is correct
6 Correct 10 ms 50268 KB Output is correct
7 Correct 11 ms 50268 KB Output is correct
8 Correct 11 ms 50268 KB Output is correct
9 Correct 11 ms 50308 KB Output is correct
10 Correct 11 ms 50420 KB Output is correct
11 Correct 10 ms 50268 KB Output is correct
12 Correct 10 ms 50264 KB Output is correct
13 Correct 11 ms 50268 KB Output is correct
14 Correct 10 ms 50268 KB Output is correct
15 Correct 11 ms 50268 KB Output is correct
16 Correct 11 ms 50268 KB Output is correct
17 Correct 10 ms 50520 KB Output is correct
18 Correct 10 ms 50268 KB Output is correct
19 Correct 11 ms 50268 KB Output is correct
20 Correct 11 ms 50268 KB Output is correct
21 Correct 11 ms 50264 KB Output is correct
22 Correct 13 ms 50524 KB Output is correct
23 Correct 13 ms 50520 KB Output is correct
24 Correct 12 ms 50524 KB Output is correct
25 Correct 13 ms 50524 KB Output is correct
26 Correct 12 ms 50524 KB Output is correct
27 Correct 12 ms 50524 KB Output is correct
28 Correct 12 ms 50524 KB Output is correct
29 Correct 12 ms 50268 KB Output is correct
30 Correct 10 ms 50268 KB Output is correct
31 Correct 12 ms 50368 KB Output is correct
32 Correct 11 ms 50264 KB Output is correct
33 Correct 10 ms 50268 KB Output is correct
34 Correct 11 ms 50264 KB Output is correct
35 Correct 11 ms 50268 KB Output is correct
36 Correct 10 ms 50268 KB Output is correct
37 Correct 13 ms 50364 KB Output is correct
38 Correct 13 ms 50264 KB Output is correct
39 Correct 11 ms 50268 KB Output is correct
40 Correct 12 ms 50268 KB Output is correct
41 Correct 11 ms 50268 KB Output is correct
42 Correct 12 ms 50268 KB Output is correct
43 Correct 12 ms 50288 KB Output is correct
44 Correct 10 ms 50268 KB Output is correct
45 Correct 13 ms 50524 KB Output is correct
46 Correct 12 ms 50524 KB Output is correct
47 Correct 11 ms 50268 KB Output is correct
48 Correct 11 ms 50268 KB Output is correct
49 Correct 12 ms 50352 KB Output is correct
50 Correct 11 ms 50268 KB Output is correct
51 Correct 10 ms 50264 KB Output is correct
52 Correct 11 ms 50268 KB Output is correct
53 Correct 11 ms 50268 KB Output is correct
54 Correct 10 ms 50268 KB Output is correct
55 Correct 12 ms 50268 KB Output is correct
56 Correct 11 ms 50264 KB Output is correct
57 Correct 12 ms 50264 KB Output is correct
58 Correct 13 ms 50524 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 50264 KB Output is correct
2 Correct 11 ms 50264 KB Output is correct
3 Correct 11 ms 50288 KB Output is correct
4 Correct 11 ms 50268 KB Output is correct
5 Correct 11 ms 50264 KB Output is correct
6 Correct 10 ms 50268 KB Output is correct
7 Correct 11 ms 50268 KB Output is correct
8 Correct 11 ms 50268 KB Output is correct
9 Correct 11 ms 50308 KB Output is correct
10 Correct 11 ms 50420 KB Output is correct
11 Correct 10 ms 50268 KB Output is correct
12 Correct 10 ms 50264 KB Output is correct
13 Correct 11 ms 50268 KB Output is correct
14 Correct 10 ms 50268 KB Output is correct
15 Correct 11 ms 50268 KB Output is correct
16 Correct 11 ms 50268 KB Output is correct
17 Correct 10 ms 50520 KB Output is correct
18 Correct 10 ms 50268 KB Output is correct
19 Correct 11 ms 50268 KB Output is correct
20 Correct 11 ms 50268 KB Output is correct
21 Correct 11 ms 50264 KB Output is correct
22 Correct 13 ms 50524 KB Output is correct
23 Correct 13 ms 50520 KB Output is correct
24 Correct 12 ms 50524 KB Output is correct
25 Correct 13 ms 50524 KB Output is correct
26 Correct 12 ms 50524 KB Output is correct
27 Correct 12 ms 50524 KB Output is correct
28 Correct 12 ms 50524 KB Output is correct
29 Correct 12 ms 50268 KB Output is correct
30 Correct 10 ms 50268 KB Output is correct
31 Correct 12 ms 50368 KB Output is correct
32 Correct 11 ms 50264 KB Output is correct
33 Correct 10 ms 50268 KB Output is correct
34 Correct 11 ms 50264 KB Output is correct
35 Correct 11 ms 50268 KB Output is correct
36 Correct 10 ms 50268 KB Output is correct
37 Correct 13 ms 50364 KB Output is correct
38 Correct 13 ms 50264 KB Output is correct
39 Correct 11 ms 50268 KB Output is correct
40 Correct 12 ms 50268 KB Output is correct
41 Correct 11 ms 50268 KB Output is correct
42 Correct 12 ms 50268 KB Output is correct
43 Correct 12 ms 50288 KB Output is correct
44 Correct 10 ms 50268 KB Output is correct
45 Correct 13 ms 50524 KB Output is correct
46 Correct 12 ms 50524 KB Output is correct
47 Correct 11 ms 50268 KB Output is correct
48 Correct 11 ms 50268 KB Output is correct
49 Correct 12 ms 50352 KB Output is correct
50 Correct 11 ms 50268 KB Output is correct
51 Correct 10 ms 50264 KB Output is correct
52 Correct 11 ms 50268 KB Output is correct
53 Correct 11 ms 50268 KB Output is correct
54 Correct 10 ms 50268 KB Output is correct
55 Correct 12 ms 50268 KB Output is correct
56 Correct 11 ms 50264 KB Output is correct
57 Correct 12 ms 50264 KB Output is correct
58 Correct 13 ms 50524 KB Output is correct
59 Correct 599 ms 101196 KB Output is correct
60 Correct 744 ms 100320 KB Output is correct
61 Correct 10 ms 50264 KB Output is correct
62 Correct 10 ms 50268 KB Output is correct
63 Correct 537 ms 96024 KB Output is correct
64 Correct 13 ms 51036 KB Output is correct
65 Correct 22 ms 53340 KB Output is correct
66 Correct 161 ms 77140 KB Output is correct
67 Correct 634 ms 109456 KB Output is correct
68 Correct 686 ms 110852 KB Output is correct
69 Correct 28 ms 52572 KB Output is correct
70 Correct 210 ms 73584 KB Output is correct
71 Correct 742 ms 128828 KB Output is correct
72 Correct 738 ms 124308 KB Output is correct
73 Correct 152 ms 63384 KB Output is correct
74 Correct 687 ms 97524 KB Output is correct
75 Correct 73 ms 57248 KB Output is correct
76 Correct 740 ms 120348 KB Output is correct
77 Correct 738 ms 121268 KB Output is correct
78 Correct 51 ms 56080 KB Output is correct
79 Correct 640 ms 106336 KB Output is correct
80 Correct 14 ms 50780 KB Output is correct
81 Correct 201 ms 71132 KB Output is correct
82 Correct 709 ms 114332 KB Output is correct
83 Correct 673 ms 97372 KB Output is correct
84 Correct 639 ms 97480 KB Output is correct
85 Correct 634 ms 97348 KB Output is correct
86 Correct 679 ms 100676 KB Output is correct
87 Correct 685 ms 100944 KB Output is correct