oj.uz

답안 #927450

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
927450 2024-02-14T21:30:23 Z Regulus Network (BOI15_net) C++17
63 / 100
 2000 ms 57464 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 = 5e5+5;
int n, dis[N], fa[N], dsu[N];
pll e[N];
vector<int> g[N];
vector<pll> v2;
 
inline int query(int x) { return (dsu[x]<0)?x : dsu[x]=query(dsu[x]); }
inline bool unite(int x, int y)
{
    x = query(x), y = query(y); if (x == y) return 0;
    dsu[y] = x; return 1;
}
 
inline void dfs(int x, int pre)
{
    dis[x] = dis[pre] + 1, fa[x] = pre;
    for (int v : g[x]) if (v != pre) dfs(v, x);
}
 
inline pll find_dis()
{
    int pos = query(1), pos2;
    dfs(pos, 0);
    for (int i=1; i <= n; ++i)
        if (dsu[i] == -1 && dis[i] > dis[pos]) pos = i;
    dfs(pos, 0), pos2 = pos;
    for (int i=1; i <= n; ++i)
        if (dsu[i] == -1 && dis[i] > dis[pos2]) pos2 = i;
    return {pos, pos2};
}
 
int main(void)
{ IO
    int i, x, y;
    
    cin >> n;
    for (i=1; i <= n-1; ++i) cin >> x >> y, e[i] = {x, y};
 
    int cnt = n;
    for (i=1; i <= n; ++i) dsu[i] = -1;
    while (cnt > 1)
    {
        //debug(cnt), endl;
        for (i=1; i <= n; ++i) g[i].clear();
        for (i=1; i <= n-1; ++i)
        {
            x = query(e[i].F), y = query(e[i].S);
            //if (x != y) debug(x), debug(y), endl;
            if (x != y) g[x].pb(y), g[y].pb(x);
        }

        for (i=1; i <= n; ++i)
        {
            if (SZ(g[i]) == cnt-1)
            {
                for (int j=1; j < SZ(g[i]); j+=2) v2.pb(g[i][j-1], g[i][j]);
                if (SZ(g[i]) & 1) v2.pb(i, g[i].back());
                break;
            }
        }
        if (i <= n) break;
 
        auto tp = find_dis();
        v2.pb(tp.F, tp.S);
        int cur = tp.S;
        do {
            if (fa[cur]) cnt -= unite(cur, fa[cur]);
            cur = fa[cur];
        } while (cur);
        //debug(dis[tp.S]-1), debug(cnt), endl;
        //for (i=1; i <= n; ++i) bug(query(i)); endl;
    }
    
    cout << SZ(v2) << '\n';
    for (auto p : v2) cout << p.F << ' ' << p.S << '\n';
 
    return 0;
}

Subtask #1
18.0 / 18.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 14940 KB Output is correct
2 Correct 3 ms 16988 KB Output is correct
3 Correct 3 ms 14940 KB Output is correct
4 Correct 5 ms 16984 KB Output is correct
5 Correct 3 ms 14940 KB Output is correct
6 Correct 3 ms 17056 KB Output is correct
7 Correct 3 ms 16988 KB Output is correct
8 Correct 3 ms 16988 KB Output is correct
9 Correct 3 ms 16988 KB Output is correct
10 Correct 4 ms 17244 KB Output is correct
11 Correct 3 ms 16988 KB Output is correct
12 Correct 4 ms 16988 KB Output is correct
13 Correct 3 ms 16988 KB Output is correct
14 Correct 4 ms 16988 KB Output is correct
15 Correct 3 ms 16988 KB Output is correct
16 Correct 3 ms 16988 KB Output is correct
17 Correct 3 ms 16988 KB Output is correct
18 Correct 3 ms 16988 KB Output is correct
19 Correct 4 ms 16996 KB Output is correct
20 Correct 3 ms 17040 KB Output is correct

Subtask #2
45.0 / 45.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 14940 KB Output is correct
2 Correct 3 ms 16988 KB Output is correct
3 Correct 3 ms 14940 KB Output is correct
4 Correct 5 ms 16984 KB Output is correct
5 Correct 3 ms 14940 KB Output is correct
6 Correct 3 ms 17056 KB Output is correct
7 Correct 3 ms 16988 KB Output is correct
8 Correct 3 ms 16988 KB Output is correct
9 Correct 3 ms 16988 KB Output is correct
10 Correct 4 ms 17244 KB Output is correct
11 Correct 3 ms 16988 KB Output is correct
12 Correct 4 ms 16988 KB Output is correct
13 Correct 3 ms 16988 KB Output is correct
14 Correct 4 ms 16988 KB Output is correct
15 Correct 3 ms 16988 KB Output is correct
16 Correct 3 ms 16988 KB Output is correct
17 Correct 3 ms 16988 KB Output is correct
18 Correct 3 ms 16988 KB Output is correct
19 Correct 4 ms 16996 KB Output is correct
20 Correct 3 ms 17040 KB Output is correct
21 Correct 4 ms 16984 KB Output is correct
22 Correct 5 ms 17240 KB Output is correct
23 Correct 4 ms 16984 KB Output is correct
24 Correct 4 ms 16988 KB Output is correct
25 Correct 18 ms 18268 KB Output is correct
26 Correct 14 ms 18052 KB Output is correct
27 Correct 13 ms 17676 KB Output is correct
28 Correct 12 ms 17764 KB Output is correct
29 Correct 8 ms 17496 KB Output is correct
30 Correct 3 ms 16988 KB Output is correct
31 Correct 13 ms 17940 KB Output is correct
32 Correct 3 ms 16984 KB Output is correct
33 Correct 4 ms 16988 KB Output is correct
34 Correct 3 ms 16988 KB Output is correct
35 Correct 3 ms 17056 KB Output is correct
36 Correct 4 ms 16988 KB Output is correct
37 Correct 3 ms 16988 KB Output is correct
38 Correct 5 ms 16988 KB Output is correct
39 Correct 3 ms 16988 KB Output is correct
40 Correct 3 ms 16988 KB Output is correct
41 Correct 3 ms 16988 KB Output is correct
42 Correct 5 ms 16988 KB Output is correct
43 Correct 4 ms 16988 KB Output is correct
44 Correct 3 ms 17056 KB Output is correct
45 Correct 5 ms 17244 KB Output is correct
46 Correct 7 ms 17304 KB Output is correct
47 Correct 3 ms 16988 KB Output is correct
48 Correct 3 ms 16988 KB Output is correct
49 Correct 5 ms 17244 KB Output is correct
50 Correct 3 ms 16988 KB Output is correct
51 Correct 4 ms 17064 KB Output is correct
52 Correct 3 ms 16988 KB Output is correct
53 Correct 4 ms 16988 KB Output is correct
54 Correct 3 ms 16988 KB Output is correct
55 Correct 4 ms 17096 KB Output is correct
56 Correct 4 ms 16988 KB Output is correct
57 Correct 3 ms 16988 KB Output is correct
58 Correct 4 ms 16984 KB Output is correct

Subtask #3
0 / 37.0

# 결과 실행 시간 메모리 Grader output
1 Correct 3 ms 14940 KB Output is correct
2 Correct 3 ms 16988 KB Output is correct
3 Correct 3 ms 14940 KB Output is correct
4 Correct 5 ms 16984 KB Output is correct
5 Correct 3 ms 14940 KB Output is correct
6 Correct 3 ms 17056 KB Output is correct
7 Correct 3 ms 16988 KB Output is correct
8 Correct 3 ms 16988 KB Output is correct
9 Correct 3 ms 16988 KB Output is correct
10 Correct 4 ms 17244 KB Output is correct
11 Correct 3 ms 16988 KB Output is correct
12 Correct 4 ms 16988 KB Output is correct
13 Correct 3 ms 16988 KB Output is correct
14 Correct 4 ms 16988 KB Output is correct
15 Correct 3 ms 16988 KB Output is correct
16 Correct 3 ms 16988 KB Output is correct
17 Correct 3 ms 16988 KB Output is correct
18 Correct 3 ms 16988 KB Output is correct
19 Correct 4 ms 16996 KB Output is correct
20 Correct 3 ms 17040 KB Output is correct
21 Correct 4 ms 16984 KB Output is correct
22 Correct 5 ms 17240 KB Output is correct
23 Correct 4 ms 16984 KB Output is correct
24 Correct 4 ms 16988 KB Output is correct
25 Correct 18 ms 18268 KB Output is correct
26 Correct 14 ms 18052 KB Output is correct
27 Correct 13 ms 17676 KB Output is correct
28 Correct 12 ms 17764 KB Output is correct
29 Correct 8 ms 17496 KB Output is correct
30 Correct 3 ms 16988 KB Output is correct
31 Correct 13 ms 17940 KB Output is correct
32 Correct 3 ms 16984 KB Output is correct
33 Correct 4 ms 16988 KB Output is correct
34 Correct 3 ms 16988 KB Output is correct
35 Correct 3 ms 17056 KB Output is correct
36 Correct 4 ms 16988 KB Output is correct
37 Correct 3 ms 16988 KB Output is correct
38 Correct 5 ms 16988 KB Output is correct
39 Correct 3 ms 16988 KB Output is correct
40 Correct 3 ms 16988 KB Output is correct
41 Correct 3 ms 16988 KB Output is correct
42 Correct 5 ms 16988 KB Output is correct
43 Correct 4 ms 16988 KB Output is correct
44 Correct 3 ms 17056 KB Output is correct
45 Correct 5 ms 17244 KB Output is correct
46 Correct 7 ms 17304 KB Output is correct
47 Correct 3 ms 16988 KB Output is correct
48 Correct 3 ms 16988 KB Output is correct
49 Correct 5 ms 17244 KB Output is correct
50 Correct 3 ms 16988 KB Output is correct
51 Correct 4 ms 17064 KB Output is correct
52 Correct 3 ms 16988 KB Output is correct
53 Correct 4 ms 16988 KB Output is correct
54 Correct 3 ms 16988 KB Output is correct
55 Correct 4 ms 17096 KB Output is correct
56 Correct 4 ms 16988 KB Output is correct
57 Correct 3 ms 16988 KB Output is correct
58 Correct 4 ms 16984 KB Output is correct
59 Execution timed out 2090 ms 57464 KB Time limit exceeded
60 Halted 0 ms 0 KB -