oj.uz

Submission #656106

# Submission time Handle Problem Language Result Execution time Memory
656106 2022-11-06T09:51:50 Z Makarooni Network (BOI15_net) C++17
100 / 100
 1215 ms 107432 KB 
/* IN THE NAME OF GOD */
/* |\/| /-\ |\| | |\/| /-\ */

#include "bits/stdc++.h"
using namespace std;

#define sz(x) (int)x.size()
#define endl '\n'
#define pb push_back
#define all(x) x.begin(), x.end()
#define F first
#define S second
#define mr make_pair
//#define int long long
#define pii pair<int, int>
typedef long double ld;
typedef long long ll;

const int N = 5e5 + 10;
const ll MOD = 1e9 + 7;
const int inf = 1e9;
const ll INF = 1e18;

vector<int> g[N];
int l[N], L, par[N], root;
set<int> le, st[N];

void dfs(int v, int p){
	for(int u : g[v]){
		if(u == p)
			continue;
		dfs(u, v);
		par[u] = v;
		l[v] += l[u];
	}
	if(sz(g[v]) == 1){
		l[v]++;
		L++;
		le.insert(v);
	}
}

void dfs2(int v){
	for(int u : g[v]){
		if(u == par[v])
			continue;
		dfs2(u);
		if(v == root)
			continue;
		if(sz(st[v]) < sz(st[u]))
			st[v].swap(st[u]);
		for(int y : st[u])
			st[v].insert(y);
		st[u].clear();
	}
	if(sz(g[v]) == 1){
		st[v].insert(v);
		le.erase(v);
	}
}

int32_t main(){
	ios_base:: sync_with_stdio(0), cin.tie(0), cout.tie(0);
	int n;
	cin >> n;
	int u, v;
	for(int i = 1; i < n; i++){
		cin >> u >> v;
		g[u].pb(v);
		g[v].pb(u);
	}
	dfs(1, 0);
	int mx = 0, sm;
	for(int i = 1; i <= n; i++){
		mx = 0, sm = 0;
		for(int u : g[i]){
			if(u == par[i])
				continue;
			mx = max(mx, l[u]);
			sm += l[u];
		}
		mx = max(mx, L - sm);
		if(mx <= L / 2 && sz(g[i]) >= 2){
			root = i;
			break;
		}
	}
	if(root == 0)
		cout << 2/0;
	dfs2(root);
	st[0] = le;
	l[0] = sz(st[0]);
	set<pii> nomily_cheat_nazan;
	for(int u : g[root]){
		if(u == par[root])
			continue;
		nomily_cheat_nazan.insert(mr(l[u], u));
	}
	if(sz(st[0]) != 0)
		nomily_cheat_nazan.insert(mr(sz(st[0]), 0));
	cout << L / 2 + (L % 2 != 0) << endl;
	while(sz(nomily_cheat_nazan) > 1){
		//cout << "$" << sz(nomily_cheat_nazan) << endl;
		auto it = nomily_cheat_nazan.end();
		auto it2 = it;
		it--;
		it2--;
		it2--;
		l[it->S]--;
		l[it2->S]--;
		//cout << "#" << it->S << " " << it2->S << endl;
		cout << *st[it2->S].begin() << " " << *st[it->S].begin() << endl;
		st[it->S].erase(*st[it->S].begin());
		st[it2->S].erase(*st[it2->S].begin());
		if(l[it->S] > 0)
			nomily_cheat_nazan.insert(mr(l[it->S], it->S));
		if(l[it2->S] > 0)
			nomily_cheat_nazan.insert(mr(l[it2->S], it2->S));
		nomily_cheat_nazan.erase(it);
		nomily_cheat_nazan.erase(it2);
		//cout << "!" << sz(nomily_cheat_nazan) << endl;
	}
	if(nomily_cheat_nazan.empty())
		return 0;
	int w = *st[nomily_cheat_nazan.begin()->S].begin(), W;
	if(par[w] == root || par[root] == w){
		if(root == 1 && w == 2)
			W = 3;
		else if(root == 2 && w == 1)
			W = 3;
		else if(root == 1)
			W = 2;
		else if(root == 2)
			W = 1;
		else if(w == 1)
			W = 2;
		else if(w == 2)
			W = 1;
		else
			W = 3;
	}
	else
		W = root;
	cout << w << " " << W;
}

Compilation message

net.cpp: In function 'int32_t main()':
net.cpp:89:12: warning: division by zero [-Wdiv-by-zero]
   89 |   cout << 2/0;
      |           ~^~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 35540 KB Output is correct
2 Correct 17 ms 35540 KB Output is correct
3 Correct 18 ms 35556 KB Output is correct
4 Correct 18 ms 35444 KB Output is correct
5 Correct 21 ms 35540 KB Output is correct
6 Correct 18 ms 35540 KB Output is correct
7 Correct 17 ms 35552 KB Output is correct
8 Correct 17 ms 35560 KB Output is correct
9 Correct 19 ms 35540 KB Output is correct
10 Correct 17 ms 35524 KB Output is correct
11 Correct 17 ms 35540 KB Output is correct
12 Correct 20 ms 35540 KB Output is correct
13 Correct 18 ms 35508 KB Output is correct
14 Correct 17 ms 35500 KB Output is correct
15 Correct 19 ms 35540 KB Output is correct
16 Correct 18 ms 35556 KB Output is correct
17 Correct 19 ms 35540 KB Output is correct
18 Correct 18 ms 35540 KB Output is correct
19 Correct 17 ms 35448 KB Output is correct
20 Correct 20 ms 35504 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 35540 KB Output is correct
2 Correct 17 ms 35540 KB Output is correct
3 Correct 18 ms 35556 KB Output is correct
4 Correct 18 ms 35444 KB Output is correct
5 Correct 21 ms 35540 KB Output is correct
6 Correct 18 ms 35540 KB Output is correct
7 Correct 17 ms 35552 KB Output is correct
8 Correct 17 ms 35560 KB Output is correct
9 Correct 19 ms 35540 KB Output is correct
10 Correct 17 ms 35524 KB Output is correct
11 Correct 17 ms 35540 KB Output is correct
12 Correct 20 ms 35540 KB Output is correct
13 Correct 18 ms 35508 KB Output is correct
14 Correct 17 ms 35500 KB Output is correct
15 Correct 19 ms 35540 KB Output is correct
16 Correct 18 ms 35556 KB Output is correct
17 Correct 19 ms 35540 KB Output is correct
18 Correct 18 ms 35540 KB Output is correct
19 Correct 17 ms 35448 KB Output is correct
20 Correct 20 ms 35504 KB Output is correct
21 Correct 17 ms 35556 KB Output is correct
22 Correct 21 ms 35820 KB Output is correct
23 Correct 18 ms 35796 KB Output is correct
24 Correct 19 ms 35796 KB Output is correct
25 Correct 18 ms 35620 KB Output is correct
26 Correct 18 ms 35664 KB Output is correct
27 Correct 19 ms 35620 KB Output is correct
28 Correct 19 ms 35716 KB Output is correct
29 Correct 19 ms 35668 KB Output is correct
30 Correct 18 ms 35540 KB Output is correct
31 Correct 18 ms 35668 KB Output is correct
32 Correct 17 ms 35540 KB Output is correct
33 Correct 18 ms 35556 KB Output is correct
34 Correct 17 ms 35480 KB Output is correct
35 Correct 17 ms 35540 KB Output is correct
36 Correct 17 ms 35540 KB Output is correct
37 Correct 17 ms 35496 KB Output is correct
38 Correct 17 ms 35540 KB Output is correct
39 Correct 18 ms 35484 KB Output is correct
40 Correct 17 ms 35444 KB Output is correct
41 Correct 18 ms 35540 KB Output is correct
42 Correct 19 ms 35540 KB Output is correct
43 Correct 18 ms 35668 KB Output is correct
44 Correct 17 ms 35548 KB Output is correct
45 Correct 17 ms 35540 KB Output is correct
46 Correct 18 ms 35540 KB Output is correct
47 Correct 18 ms 35444 KB Output is correct
48 Correct 19 ms 35580 KB Output is correct
49 Correct 19 ms 35668 KB Output is correct
50 Correct 17 ms 35548 KB Output is correct
51 Correct 19 ms 35532 KB Output is correct
52 Correct 17 ms 35572 KB Output is correct
53 Correct 17 ms 35540 KB Output is correct
54 Correct 19 ms 35552 KB Output is correct
55 Correct 17 ms 35540 KB Output is correct
56 Correct 17 ms 35484 KB Output is correct
57 Correct 18 ms 35540 KB Output is correct
58 Correct 18 ms 35668 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 17 ms 35540 KB Output is correct
2 Correct 17 ms 35540 KB Output is correct
3 Correct 18 ms 35556 KB Output is correct
4 Correct 18 ms 35444 KB Output is correct
5 Correct 21 ms 35540 KB Output is correct
6 Correct 18 ms 35540 KB Output is correct
7 Correct 17 ms 35552 KB Output is correct
8 Correct 17 ms 35560 KB Output is correct
9 Correct 19 ms 35540 KB Output is correct
10 Correct 17 ms 35524 KB Output is correct
11 Correct 17 ms 35540 KB Output is correct
12 Correct 20 ms 35540 KB Output is correct
13 Correct 18 ms 35508 KB Output is correct
14 Correct 17 ms 35500 KB Output is correct
15 Correct 19 ms 35540 KB Output is correct
16 Correct 18 ms 35556 KB Output is correct
17 Correct 19 ms 35540 KB Output is correct
18 Correct 18 ms 35540 KB Output is correct
19 Correct 17 ms 35448 KB Output is correct
20 Correct 20 ms 35504 KB Output is correct
21 Correct 17 ms 35556 KB Output is correct
22 Correct 21 ms 35820 KB Output is correct
23 Correct 18 ms 35796 KB Output is correct
24 Correct 19 ms 35796 KB Output is correct
25 Correct 18 ms 35620 KB Output is correct
26 Correct 18 ms 35664 KB Output is correct
27 Correct 19 ms 35620 KB Output is correct
28 Correct 19 ms 35716 KB Output is correct
29 Correct 19 ms 35668 KB Output is correct
30 Correct 18 ms 35540 KB Output is correct
31 Correct 18 ms 35668 KB Output is correct
32 Correct 17 ms 35540 KB Output is correct
33 Correct 18 ms 35556 KB Output is correct
34 Correct 17 ms 35480 KB Output is correct
35 Correct 17 ms 35540 KB Output is correct
36 Correct 17 ms 35540 KB Output is correct
37 Correct 17 ms 35496 KB Output is correct
38 Correct 17 ms 35540 KB Output is correct
39 Correct 18 ms 35484 KB Output is correct
40 Correct 17 ms 35444 KB Output is correct
41 Correct 18 ms 35540 KB Output is correct
42 Correct 19 ms 35540 KB Output is correct
43 Correct 18 ms 35668 KB Output is correct
44 Correct 17 ms 35548 KB Output is correct
45 Correct 17 ms 35540 KB Output is correct
46 Correct 18 ms 35540 KB Output is correct
47 Correct 18 ms 35444 KB Output is correct
48 Correct 19 ms 35580 KB Output is correct
49 Correct 19 ms 35668 KB Output is correct
50 Correct 17 ms 35548 KB Output is correct
51 Correct 19 ms 35532 KB Output is correct
52 Correct 17 ms 35572 KB Output is correct
53 Correct 17 ms 35540 KB Output is correct
54 Correct 19 ms 35552 KB Output is correct
55 Correct 17 ms 35540 KB Output is correct
56 Correct 17 ms 35484 KB Output is correct
57 Correct 18 ms 35540 KB Output is correct
58 Correct 18 ms 35668 KB Output is correct
59 Correct 862 ms 76848 KB Output is correct
60 Correct 1053 ms 77004 KB Output is correct
61 Correct 18 ms 35540 KB Output is correct
62 Correct 17 ms 35460 KB Output is correct
63 Correct 763 ms 72404 KB Output is correct
64 Correct 19 ms 36052 KB Output is correct
65 Correct 26 ms 38232 KB Output is correct
66 Correct 142 ms 56084 KB Output is correct
67 Correct 564 ms 92832 KB Output is correct
68 Correct 545 ms 90980 KB Output is correct
69 Correct 32 ms 37580 KB Output is correct
70 Correct 255 ms 56460 KB Output is correct
71 Correct 1215 ms 107432 KB Output is correct
72 Correct 1149 ms 102104 KB Output is correct
73 Correct 160 ms 46284 KB Output is correct
74 Correct 858 ms 72556 KB Output is correct
75 Correct 66 ms 42940 KB Output is correct
76 Correct 1212 ms 93992 KB Output is correct
77 Correct 1214 ms 95664 KB Output is correct
78 Correct 62 ms 40600 KB Output is correct
79 Correct 559 ms 78480 KB Output is correct
80 Correct 25 ms 35976 KB Output is correct
81 Correct 216 ms 55212 KB Output is correct
82 Correct 955 ms 94084 KB Output is correct
83 Correct 872 ms 71404 KB Output is correct
84 Correct 816 ms 73720 KB Output is correct
85 Correct 916 ms 71404 KB Output is correct
86 Correct 1036 ms 77352 KB Output is correct
87 Correct 1010 ms 78332 KB Output is correct