oj.uz

Submission #155038

# Submission time Handle Problem Language Result Execution time Memory
155038 2019-09-26T03:00:21 Z junodeveloper Network (BOI15_net) C++14
100 / 100
 710 ms 116472 KB 
#include <bits/stdc++.h>
#define sz(x) ((int)x.size())
#define all(x) (x).begin(), (x).end()
#define fi first
#define se second
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;
const int maxn=500000;
int n,D[maxn+10][2];
vector<int> adj[maxn+10];
vector<pii> res;
void solve(int p,int u) {
	vector<int> ones,twos;
	for(auto& it:adj[u]) {
		if(it==p) continue;
		solve(u,it);
		if(D[it][1]) twos.push_back(it);
		else if(D[it][0]) ones.push_back(it);
	}
	while(sz(twos)>=2) {
		res.push_back({D[twos.back()][1],D[twos[sz(twos)-2]][1]});
		ones.push_back(twos.back());
		ones.push_back(twos[sz(twos)-2]);
		twos.pop_back();twos.pop_back();
	}
	if(!twos.empty()&&ones.empty()) {
		D[u][0]=D[twos[0]][0];
		D[u][1]=D[twos[0]][1];
		return;
	}
	if(!twos.empty()) {
		res.push_back({D[twos.back()][1],D[ones.back()][0]});
		ones.pop_back();ones.push_back(twos.back());
		twos.pop_back();
	}
	while(sz(ones)>=3) {
		res.push_back({D[ones.back()][0],D[ones[sz(ones)-2]][0]});
		ones.pop_back();ones.pop_back();
	}
	if(u==p) {
		if(sz(ones)==1) res.push_back({u,D[ones.back()][0]});
		else if(sz(ones)==2) res.push_back({D[ones.back()][0],D[ones[sz(ones)-2]][0]});
	} else if(sz(adj[u])==1) D[u][0]=u;
	else {
		if(sz(ones)>=1) D[u][0]=D[ones[0]][0];
		if(sz(ones)>=2) D[u][1]=D[ones[1]][0];
	}
}
int main() {
	scanf("%d",&n);
	int i;
	for(i=0;i+1<n;i++) {
		int u,v;
		scanf("%d%d",&u,&v);
		adj[u].push_back(v);
		adj[v].push_back(u);
	}
	int rt=-1;
	for(i=1;i<=n;i++) if(sz(adj[i])!=1) rt=i;
	solve(rt,rt);
	printf("%d\n",sz(res));
	for(auto& it:res) printf("%d %d\n",it.fi,it.se);
	return 0;
}

Compilation message

net.cpp: In function 'int main()':
net.cpp:53:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d",&n);
  ~~~~~^~~~~~~~~
net.cpp:57:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d",&u,&v);
   ~~~~~^~~~~~~~~~~~~~

Subtask #1
18.0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 12152 KB Output is correct
2 Correct 12 ms 12024 KB Output is correct
3 Correct 12 ms 12024 KB Output is correct
4 Correct 13 ms 12152 KB Output is correct
5 Correct 12 ms 12024 KB Output is correct
6 Correct 13 ms 12152 KB Output is correct
7 Correct 12 ms 12024 KB Output is correct
8 Correct 12 ms 12024 KB Output is correct
9 Correct 12 ms 12152 KB Output is correct
10 Correct 13 ms 12024 KB Output is correct
11 Correct 12 ms 12024 KB Output is correct
12 Correct 12 ms 12152 KB Output is correct
13 Correct 12 ms 12024 KB Output is correct
14 Correct 12 ms 12024 KB Output is correct
15 Correct 12 ms 12024 KB Output is correct
16 Correct 12 ms 12024 KB Output is correct
17 Correct 12 ms 12024 KB Output is correct
18 Correct 12 ms 12024 KB Output is correct
19 Correct 12 ms 12024 KB Output is correct
20 Correct 12 ms 12024 KB Output is correct

Subtask #2
45.0 / 45.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 12152 KB Output is correct
2 Correct 12 ms 12024 KB Output is correct
3 Correct 12 ms 12024 KB Output is correct
4 Correct 13 ms 12152 KB Output is correct
5 Correct 12 ms 12024 KB Output is correct
6 Correct 13 ms 12152 KB Output is correct
7 Correct 12 ms 12024 KB Output is correct
8 Correct 12 ms 12024 KB Output is correct
9 Correct 12 ms 12152 KB Output is correct
10 Correct 13 ms 12024 KB Output is correct
11 Correct 12 ms 12024 KB Output is correct
12 Correct 12 ms 12152 KB Output is correct
13 Correct 12 ms 12024 KB Output is correct
14 Correct 12 ms 12024 KB Output is correct
15 Correct 12 ms 12024 KB Output is correct
16 Correct 12 ms 12024 KB Output is correct
17 Correct 12 ms 12024 KB Output is correct
18 Correct 12 ms 12024 KB Output is correct
19 Correct 12 ms 12024 KB Output is correct
20 Correct 12 ms 12024 KB Output is correct
21 Correct 12 ms 12280 KB Output is correct
22 Correct 13 ms 12152 KB Output is correct
23 Correct 13 ms 12280 KB Output is correct
24 Correct 14 ms 12152 KB Output is correct
25 Correct 13 ms 12156 KB Output is correct
26 Correct 13 ms 12152 KB Output is correct
27 Correct 13 ms 12152 KB Output is correct
28 Correct 13 ms 12152 KB Output is correct
29 Correct 14 ms 12152 KB Output is correct
30 Correct 12 ms 12024 KB Output is correct
31 Correct 13 ms 12152 KB Output is correct
32 Correct 12 ms 12024 KB Output is correct
33 Correct 12 ms 12024 KB Output is correct
34 Correct 12 ms 12040 KB Output is correct
35 Correct 12 ms 12024 KB Output is correct
36 Correct 12 ms 12024 KB Output is correct
37 Correct 12 ms 12152 KB Output is correct
38 Correct 13 ms 12152 KB Output is correct
39 Correct 12 ms 12124 KB Output is correct
40 Correct 12 ms 12024 KB Output is correct
41 Correct 12 ms 12024 KB Output is correct
42 Correct 13 ms 12152 KB Output is correct
43 Correct 13 ms 12152 KB Output is correct
44 Correct 12 ms 12024 KB Output is correct
45 Correct 13 ms 12152 KB Output is correct
46 Correct 15 ms 12164 KB Output is correct
47 Correct 12 ms 12024 KB Output is correct
48 Correct 12 ms 12152 KB Output is correct
49 Correct 13 ms 12152 KB Output is correct
50 Correct 12 ms 12152 KB Output is correct
51 Correct 12 ms 12028 KB Output is correct
52 Correct 12 ms 12152 KB Output is correct
53 Correct 13 ms 12152 KB Output is correct
54 Correct 12 ms 12024 KB Output is correct
55 Correct 12 ms 12152 KB Output is correct
56 Correct 12 ms 12024 KB Output is correct
57 Correct 13 ms 12152 KB Output is correct
58 Correct 15 ms 12280 KB Output is correct

Subtask #3
37.0 / 37.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 12152 KB Output is correct
2 Correct 12 ms 12024 KB Output is correct
3 Correct 12 ms 12024 KB Output is correct
4 Correct 13 ms 12152 KB Output is correct
5 Correct 12 ms 12024 KB Output is correct
6 Correct 13 ms 12152 KB Output is correct
7 Correct 12 ms 12024 KB Output is correct
8 Correct 12 ms 12024 KB Output is correct
9 Correct 12 ms 12152 KB Output is correct
10 Correct 13 ms 12024 KB Output is correct
11 Correct 12 ms 12024 KB Output is correct
12 Correct 12 ms 12152 KB Output is correct
13 Correct 12 ms 12024 KB Output is correct
14 Correct 12 ms 12024 KB Output is correct
15 Correct 12 ms 12024 KB Output is correct
16 Correct 12 ms 12024 KB Output is correct
17 Correct 12 ms 12024 KB Output is correct
18 Correct 12 ms 12024 KB Output is correct
19 Correct 12 ms 12024 KB Output is correct
20 Correct 12 ms 12024 KB Output is correct
21 Correct 12 ms 12280 KB Output is correct
22 Correct 13 ms 12152 KB Output is correct
23 Correct 13 ms 12280 KB Output is correct
24 Correct 14 ms 12152 KB Output is correct
25 Correct 13 ms 12156 KB Output is correct
26 Correct 13 ms 12152 KB Output is correct
27 Correct 13 ms 12152 KB Output is correct
28 Correct 13 ms 12152 KB Output is correct
29 Correct 14 ms 12152 KB Output is correct
30 Correct 12 ms 12024 KB Output is correct
31 Correct 13 ms 12152 KB Output is correct
32 Correct 12 ms 12024 KB Output is correct
33 Correct 12 ms 12024 KB Output is correct
34 Correct 12 ms 12040 KB Output is correct
35 Correct 12 ms 12024 KB Output is correct
36 Correct 12 ms 12024 KB Output is correct
37 Correct 12 ms 12152 KB Output is correct
38 Correct 13 ms 12152 KB Output is correct
39 Correct 12 ms 12124 KB Output is correct
40 Correct 12 ms 12024 KB Output is correct
41 Correct 12 ms 12024 KB Output is correct
42 Correct 13 ms 12152 KB Output is correct
43 Correct 13 ms 12152 KB Output is correct
44 Correct 12 ms 12024 KB Output is correct
45 Correct 13 ms 12152 KB Output is correct
46 Correct 15 ms 12164 KB Output is correct
47 Correct 12 ms 12024 KB Output is correct
48 Correct 12 ms 12152 KB Output is correct
49 Correct 13 ms 12152 KB Output is correct
50 Correct 12 ms 12152 KB Output is correct
51 Correct 12 ms 12028 KB Output is correct
52 Correct 12 ms 12152 KB Output is correct
53 Correct 13 ms 12152 KB Output is correct
54 Correct 12 ms 12024 KB Output is correct
55 Correct 12 ms 12152 KB Output is correct
56 Correct 12 ms 12024 KB Output is correct
57 Correct 13 ms 12152 KB Output is correct
58 Correct 15 ms 12280 KB Output is correct
59 Correct 507 ms 39736 KB Output is correct
60 Correct 576 ms 42828 KB Output is correct
61 Correct 13 ms 12024 KB Output is correct
62 Correct 12 ms 12280 KB Output is correct
63 Correct 454 ms 37648 KB Output is correct
64 Correct 16 ms 12792 KB Output is correct
65 Correct 29 ms 15608 KB Output is correct
66 Correct 222 ms 39060 KB Output is correct
67 Correct 710 ms 116472 KB Output is correct
68 Correct 706 ms 91452 KB Output is correct
69 Correct 20 ms 13048 KB Output is correct
70 Correct 117 ms 23156 KB Output is correct
71 Correct 373 ms 45880 KB Output is correct
72 Correct 389 ms 44580 KB Output is correct
73 Correct 139 ms 20208 KB Output is correct
74 Correct 619 ms 41656 KB Output is correct
75 Correct 42 ms 15844 KB Output is correct
76 Correct 385 ms 45548 KB Output is correct
77 Correct 410 ms 45624 KB Output is correct
78 Correct 50 ms 17784 KB Output is correct
79 Correct 675 ms 74104 KB Output is correct
80 Correct 15 ms 12408 KB Output is correct
81 Correct 148 ms 23180 KB Output is correct
82 Correct 597 ms 43412 KB Output is correct
83 Correct 633 ms 42100 KB Output is correct
84 Correct 602 ms 41716 KB Output is correct
85 Correct 635 ms 41736 KB Output is correct
86 Correct 679 ms 42716 KB Output is correct
87 Correct 602 ms 42732 KB Output is correct