oj.uz

답안 #717501

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
717501 2023-04-02T03:01:15 Z Charizard2021 Network (BOI15_net) C++17
18 / 100
 48 ms 72040 KB 
#include<bits/stdc++.h>
using namespace std;
const int N = 500001;
#define IOS ios::sync_with_stdio(false);; cin.tie(NULL)
bool visited[N];
int LeavesInsubtee[N];
vector<int> adj[N];
vector<int> res[N];
vector<int> v2[N];
int n;
int ans = 0;
int cur_ans = 0;
int subtreeValue = 0;
void dfs(int u){
    visited[u] = true;
    if((int)adj[u].size() == 1){
        LeavesInsubtee[u] = 1;
    }
    for(int v : adj[u]){
        if(!visited[v]){
            dfs(v);
            LeavesInsubtee[u] += LeavesInsubtee[v];
        }
    }
}
void dfs2(int u){
    visited[u] = true;
    if((int)adj[u].size() == 1){
        res[subtreeValue].push_back(u);
    }
    for(int v : adj[u]){
        if(!visited[v]){
            dfs2(v);
        }
    }
}
int cutlocation(int u){
    visited[u] = true;
    for(int v : adj[u]){
        if(!visited[v]){
            if(LeavesInsubtee[v] > floor((cur_ans)/2)){
                return cutlocation(v);
            }
        }
    }
    return u;
}
int cut(int u){
    dfs(1);
    for(int i = 1; i <= n; i++){
        visited[i] = false;
    }
    int x = cutlocation(1);
    for(int i = 1; i <= n; i++){
        visited[i] = false;
    }
    visited[x] = true;
    for(int v : adj[x]){
        subtreeValue++;
        dfs2(v);
    }
    return x;
}
struct cmp{
    bool operator()(const int &a, const int &b) const{
        if(res[a].size() == res[b].size()){
            return a < b;
        }
        return res[a].size() > res[b].size();
    }
};
int main(){
    IOS;
    cin >> n;
    for(int i = 0; i < n - 1; i++){
        int a, b;
        cin >> a >> b;
        adj[a].push_back(b);
        adj[b].push_back(a);
    }
    for(int i = 1; i <= n; i++){
        if((int)adj[i].size() == 1){
            ans++;
        }
    }
    cur_ans = ans;
    ans = (ans + 1)/2;
    cout << ans << "\n";
    cut(n);
    vector<int> v;
    vector<int> res2[subtreeValue + 1];
    for(int i = 1; i <= subtreeValue; i++){
        v2[res[i].size()].push_back(i);
        res2[i] = res[i];
    }
    int first_pointer = -1;
    int second_pointer = -1;
    for(int i = N - 1; i > 0; i--){
        if(!v2[i].empty() && first_pointer == -1){
            first_pointer = i;
        }
        if(v2[i].size() > 1 && second_pointer == -1){
            second_pointer = i;
        }
    }
    while(first_pointer != 0){
        int x = v2[first_pointer].back();
        v.push_back(res[x].back());
        v2[first_pointer].pop_back();
        res[x].pop_back();
        if(second_pointer != 0 && v2[second_pointer].size() != 0){
            int y = v2[second_pointer].back();
            v.push_back(res[y].back());
            v2[second_pointer].pop_back();
            res[y].pop_back();
            if(!res[y].empty()){
                v2[res[y].size()].push_back(y);
            }
            if((first_pointer == second_pointer && v2[res[y].size() + 1].size() <= 1) || (first_pointer != second_pointer && v2[res[y].size() + 1].size() == 0)){
                second_pointer--;
            }
        }
        if(!res[x].empty()){
            v2[res[x].size()].push_back(x);
        }
        if(v2[res[x].size() + 1].size() == 0){
            first_pointer--;
        }
    }
    if(v.size() % 2 == 1){
        for(int i = 1; i <= subtreeValue; i++){
            for(int j = 0; j < res2[i].size(); j++){
                if(res2[i][j] != v.back()){
                    v.push_back(res2[i][j]);
                    break;
                }
            }
            if(v.size() % 2== 0){
                break;
            }
        }
    }
    for(int i = 0; i < (int)v.size(); i += 2){
        cout << v[i] << " " << v[i + 1] << "\n";
    }
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:132:30: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  132 |             for(int j = 0; j < res2[i].size(); j++){
      |                            ~~^~~~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

# 결과 실행 시간 메모리 Grader output
1 Correct 23 ms 35540 KB Output is correct
2 Correct 20 ms 35488 KB Output is correct
3 Correct 20 ms 35588 KB Output is correct
4 Correct 24 ms 35428 KB Output is correct
5 Correct 18 ms 35540 KB Output is correct
6 Correct 18 ms 35536 KB Output is correct
7 Correct 19 ms 35672 KB Output is correct
8 Correct 21 ms 35492 KB Output is correct
9 Correct 21 ms 35540 KB Output is correct
10 Correct 20 ms 35512 KB Output is correct
11 Correct 26 ms 35536 KB Output is correct
12 Correct 23 ms 35444 KB Output is correct
13 Correct 22 ms 35540 KB Output is correct
14 Correct 18 ms 35440 KB Output is correct
15 Correct 18 ms 35540 KB Output is correct
16 Correct 19 ms 35456 KB Output is correct
17 Correct 19 ms 35568 KB Output is correct
18 Correct 18 ms 35540 KB Output is correct
19 Correct 21 ms 35560 KB Output is correct
20 Correct 22 ms 35440 KB Output is correct

Subtask #2
0 / 45.0

# 결과 실행 시간 메모리 Grader output
1 Correct 23 ms 35540 KB Output is correct
2 Correct 20 ms 35488 KB Output is correct
3 Correct 20 ms 35588 KB Output is correct
4 Correct 24 ms 35428 KB Output is correct
5 Correct 18 ms 35540 KB Output is correct
6 Correct 18 ms 35536 KB Output is correct
7 Correct 19 ms 35672 KB Output is correct
8 Correct 21 ms 35492 KB Output is correct
9 Correct 21 ms 35540 KB Output is correct
10 Correct 20 ms 35512 KB Output is correct
11 Correct 26 ms 35536 KB Output is correct
12 Correct 23 ms 35444 KB Output is correct
13 Correct 22 ms 35540 KB Output is correct
14 Correct 18 ms 35440 KB Output is correct
15 Correct 18 ms 35540 KB Output is correct
16 Correct 19 ms 35456 KB Output is correct
17 Correct 19 ms 35568 KB Output is correct
18 Correct 18 ms 35540 KB Output is correct
19 Correct 21 ms 35560 KB Output is correct
20 Correct 22 ms 35440 KB Output is correct
21 Correct 24 ms 35540 KB Output is correct
22 Correct 22 ms 35796 KB Output is correct
23 Correct 20 ms 35764 KB Output is correct
24 Correct 21 ms 35828 KB Output is correct
25 Correct 20 ms 35696 KB Output is correct
26 Correct 22 ms 35696 KB Output is correct
27 Runtime error 48 ms 72040 KB Execution killed with signal 11
28 Halted 0 ms 0 KB -

Subtask #3
0 / 37.0

# 결과 실행 시간 메모리 Grader output
1 Correct 23 ms 35540 KB Output is correct
2 Correct 20 ms 35488 KB Output is correct
3 Correct 20 ms 35588 KB Output is correct
4 Correct 24 ms 35428 KB Output is correct
5 Correct 18 ms 35540 KB Output is correct
6 Correct 18 ms 35536 KB Output is correct
7 Correct 19 ms 35672 KB Output is correct
8 Correct 21 ms 35492 KB Output is correct
9 Correct 21 ms 35540 KB Output is correct
10 Correct 20 ms 35512 KB Output is correct
11 Correct 26 ms 35536 KB Output is correct
12 Correct 23 ms 35444 KB Output is correct
13 Correct 22 ms 35540 KB Output is correct
14 Correct 18 ms 35440 KB Output is correct
15 Correct 18 ms 35540 KB Output is correct
16 Correct 19 ms 35456 KB Output is correct
17 Correct 19 ms 35568 KB Output is correct
18 Correct 18 ms 35540 KB Output is correct
19 Correct 21 ms 35560 KB Output is correct
20 Correct 22 ms 35440 KB Output is correct
21 Correct 24 ms 35540 KB Output is correct
22 Correct 22 ms 35796 KB Output is correct
23 Correct 20 ms 35764 KB Output is correct
24 Correct 21 ms 35828 KB Output is correct
25 Correct 20 ms 35696 KB Output is correct
26 Correct 22 ms 35696 KB Output is correct
27 Runtime error 48 ms 72040 KB Execution killed with signal 11
28 Halted 0 ms 0 KB -