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Submission #928633

# Submission time Handle Problem Language Result Execution time Memory
928633 2024-02-16T21:42:41 Z Regulus Network (BOI15_net) C++17
63 / 100
 5 ms 10072 KB 
#include <bits/stdc++.h>
#define IO ios::sync_with_stdio(false);cin.tie(0);
#define debug(x) cerr << #x << " = " << (x) << ' '
#define bug(x) cerr << (x) << ' '
#define endl cerr << '\n'
#define all(v) (v).begin(), (v).end()
#define SZ(v) (ll)(v).size()
#define lowbit(x) (x)&-(x)
#define pb emplace_back
#define F first
#define S second
using namespace std;
using ll = long long;
using pll = pair<ll, ll>;

const int N = 1e5+5;
int sz[N], cnt, pos, mxs[N];
vector<int> g[N], vec[N];
vector<pll> ans;
priority_queue<pll> pq;

inline void dfs(int x, int fa)
{
    if (SZ(g[x]) == 1) sz[x] = 1;
    for (int v : g[x])
    {
        if (v == fa) continue;
        dfs(v, x), sz[x] += sz[v];
        mxs[x] = max(mxs[x], sz[v]);
    }
    mxs[x] = max(mxs[x], cnt-sz[x]);
    if (mxs[x] < mxs[pos]) pos = x;
}

inline void dfs2(int x, int fa, int d)
{
    if (SZ(g[x]) == 1) vec[d].pb(x);
    for (int v : g[x]) if (v != fa) dfs2(v, x, d);
}

int main(void)
{ IO
    int n, i;

    cin >> n;
    for (i=0; i < n-1; ++i)
    { int x, y; cin >> x >> y, g[x].pb(y), g[y].pb(x); }

    for (i=1; i <= n; ++i) if (SZ(g[i]) == 1) ++cnt;
    pos = 0, mxs[0] = 2e9, dfs(1, 0);
    int tot = 0;
    for (int v : g[pos])
    {
        dfs2(v, pos, ++tot);
        pq.push({SZ(vec[tot]), tot});
    }

    while (SZ(pq) > 1)
    {
        auto p = pq.top(); pq.pop();
        auto p2 = pq.top(); pq.pop();
        ans.pb(vec[p.S].back(), vec[p2.S].back());
        vec[p.S].pop_back(), vec[p2.S].pop_back();
        if (!vec[p.S].empty()) pq.push({SZ(vec[p.S]), p.S});
        if (!vec[p2.S].empty()) pq.push({SZ(vec[p2.S]), p2.S});
    }
    if (!pq.empty())
    {
        int x = pq.top().S;
        while (!vec[x].empty())
            ans.pb(vec[x].back(), pos), vec[x].pop_back();
    }

    cout << SZ(ans) << '\n';
    for (auto p : ans) cout << p.F << ' ' << p.S << '\n';


    return 0;
}

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4956 KB Output is correct
2 Correct 1 ms 4956 KB Output is correct
3 Correct 1 ms 4956 KB Output is correct
4 Correct 1 ms 4956 KB Output is correct
5 Correct 1 ms 5160 KB Output is correct
6 Correct 1 ms 4956 KB Output is correct
7 Correct 1 ms 5164 KB Output is correct
8 Correct 2 ms 4956 KB Output is correct
9 Correct 1 ms 4956 KB Output is correct
10 Correct 1 ms 4952 KB Output is correct
11 Correct 1 ms 4956 KB Output is correct
12 Correct 1 ms 4956 KB Output is correct
13 Correct 1 ms 4952 KB Output is correct
14 Correct 1 ms 4956 KB Output is correct
15 Correct 2 ms 4952 KB Output is correct
16 Correct 1 ms 4952 KB Output is correct
17 Correct 1 ms 4952 KB Output is correct
18 Correct 2 ms 5040 KB Output is correct
19 Correct 1 ms 4956 KB Output is correct
20 Correct 2 ms 5180 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4956 KB Output is correct
2 Correct 1 ms 4956 KB Output is correct
3 Correct 1 ms 4956 KB Output is correct
4 Correct 1 ms 4956 KB Output is correct
5 Correct 1 ms 5160 KB Output is correct
6 Correct 1 ms 4956 KB Output is correct
7 Correct 1 ms 5164 KB Output is correct
8 Correct 2 ms 4956 KB Output is correct
9 Correct 1 ms 4956 KB Output is correct
10 Correct 1 ms 4952 KB Output is correct
11 Correct 1 ms 4956 KB Output is correct
12 Correct 1 ms 4956 KB Output is correct
13 Correct 1 ms 4952 KB Output is correct
14 Correct 1 ms 4956 KB Output is correct
15 Correct 2 ms 4952 KB Output is correct
16 Correct 1 ms 4952 KB Output is correct
17 Correct 1 ms 4952 KB Output is correct
18 Correct 2 ms 5040 KB Output is correct
19 Correct 1 ms 4956 KB Output is correct
20 Correct 2 ms 5180 KB Output is correct
21 Correct 1 ms 4952 KB Output is correct
22 Correct 2 ms 5212 KB Output is correct
23 Correct 2 ms 5212 KB Output is correct
24 Correct 2 ms 5212 KB Output is correct
25 Correct 2 ms 5212 KB Output is correct
26 Correct 2 ms 5212 KB Output is correct
27 Correct 2 ms 5212 KB Output is correct
28 Correct 2 ms 5212 KB Output is correct
29 Correct 2 ms 5208 KB Output is correct
30 Correct 2 ms 4956 KB Output is correct
31 Correct 2 ms 5212 KB Output is correct
32 Correct 1 ms 4956 KB Output is correct
33 Correct 2 ms 4952 KB Output is correct
34 Correct 2 ms 5156 KB Output is correct
35 Correct 1 ms 4956 KB Output is correct
36 Correct 1 ms 5160 KB Output is correct
37 Correct 1 ms 4952 KB Output is correct
38 Correct 2 ms 5208 KB Output is correct
39 Correct 1 ms 5164 KB Output is correct
40 Correct 1 ms 4956 KB Output is correct
41 Correct 1 ms 4956 KB Output is correct
42 Correct 2 ms 5212 KB Output is correct
43 Correct 2 ms 5208 KB Output is correct
44 Correct 1 ms 4956 KB Output is correct
45 Correct 1 ms 4956 KB Output is correct
46 Correct 2 ms 5128 KB Output is correct
47 Correct 2 ms 5208 KB Output is correct
48 Correct 2 ms 4956 KB Output is correct
49 Correct 2 ms 5212 KB Output is correct
50 Correct 1 ms 4956 KB Output is correct
51 Correct 1 ms 4956 KB Output is correct
52 Correct 1 ms 4956 KB Output is correct
53 Correct 2 ms 5212 KB Output is correct
54 Correct 1 ms 4956 KB Output is correct
55 Correct 2 ms 4956 KB Output is correct
56 Correct 1 ms 4956 KB Output is correct
57 Correct 2 ms 5208 KB Output is correct
58 Correct 2 ms 5172 KB Output is correct

Subtask #3
0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 4956 KB Output is correct
2 Correct 1 ms 4956 KB Output is correct
3 Correct 1 ms 4956 KB Output is correct
4 Correct 1 ms 4956 KB Output is correct
5 Correct 1 ms 5160 KB Output is correct
6 Correct 1 ms 4956 KB Output is correct
7 Correct 1 ms 5164 KB Output is correct
8 Correct 2 ms 4956 KB Output is correct
9 Correct 1 ms 4956 KB Output is correct
10 Correct 1 ms 4952 KB Output is correct
11 Correct 1 ms 4956 KB Output is correct
12 Correct 1 ms 4956 KB Output is correct
13 Correct 1 ms 4952 KB Output is correct
14 Correct 1 ms 4956 KB Output is correct
15 Correct 2 ms 4952 KB Output is correct
16 Correct 1 ms 4952 KB Output is correct
17 Correct 1 ms 4952 KB Output is correct
18 Correct 2 ms 5040 KB Output is correct
19 Correct 1 ms 4956 KB Output is correct
20 Correct 2 ms 5180 KB Output is correct
21 Correct 1 ms 4952 KB Output is correct
22 Correct 2 ms 5212 KB Output is correct
23 Correct 2 ms 5212 KB Output is correct
24 Correct 2 ms 5212 KB Output is correct
25 Correct 2 ms 5212 KB Output is correct
26 Correct 2 ms 5212 KB Output is correct
27 Correct 2 ms 5212 KB Output is correct
28 Correct 2 ms 5212 KB Output is correct
29 Correct 2 ms 5208 KB Output is correct
30 Correct 2 ms 4956 KB Output is correct
31 Correct 2 ms 5212 KB Output is correct
32 Correct 1 ms 4956 KB Output is correct
33 Correct 2 ms 4952 KB Output is correct
34 Correct 2 ms 5156 KB Output is correct
35 Correct 1 ms 4956 KB Output is correct
36 Correct 1 ms 5160 KB Output is correct
37 Correct 1 ms 4952 KB Output is correct
38 Correct 2 ms 5208 KB Output is correct
39 Correct 1 ms 5164 KB Output is correct
40 Correct 1 ms 4956 KB Output is correct
41 Correct 1 ms 4956 KB Output is correct
42 Correct 2 ms 5212 KB Output is correct
43 Correct 2 ms 5208 KB Output is correct
44 Correct 1 ms 4956 KB Output is correct
45 Correct 1 ms 4956 KB Output is correct
46 Correct 2 ms 5128 KB Output is correct
47 Correct 2 ms 5208 KB Output is correct
48 Correct 2 ms 4956 KB Output is correct
49 Correct 2 ms 5212 KB Output is correct
50 Correct 1 ms 4956 KB Output is correct
51 Correct 1 ms 4956 KB Output is correct
52 Correct 1 ms 4956 KB Output is correct
53 Correct 2 ms 5212 KB Output is correct
54 Correct 1 ms 4956 KB Output is correct
55 Correct 2 ms 4956 KB Output is correct
56 Correct 1 ms 4956 KB Output is correct
57 Correct 2 ms 5208 KB Output is correct
58 Correct 2 ms 5172 KB Output is correct
59 Runtime error 5 ms 10072 KB Execution killed with signal 11
60 Halted 0 ms 0 KB -