| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 394620 |
2021-04-27T06:04:39 Z |
minoum |
Network (BOI15_net) |
C++17 |
|
612 ms |
53440 KB |
#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
const int MAXN = 5e5+10;
int n, st[MAXN], tim = 0, r = -1, lfc = 0, par[MAXN];
vector <int> adj[MAXN], tof;
vector <pair<int,int>> ans;
bool dead[MAXN];
void dfs(int v, int parv){
st[v] = tim++;
if((int)adj[v].size()==1) ans.push_back({st[v],v});
for(int u: adj[v])
if(u!=parv && !dead[u]) dfs(u,v);
return;
}
void dfs1(int v, int parv){
for(int u: adj[v])
if(u != parv){
par[u] = v;
dfs1(u,v);
}
return;
}
int main()
{
ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
cin >> n;
for(int i = 0; i < n-1; i++){
int u,v;
cin >> u >> v; u--; v--;
adj[v].push_back(u);
adj[u].push_back(v);
}
for(int i = 0; i < n; i++)
if((int)adj[i].size()==1) tof.push_back(i);
if(tof.size()==2){
cout << 1 << '\n' << tof[0]+1 << " " << tof[1]+1 << '\n';
return 0;
}
for(int i = 0; i < n; i++)
if((int)adj[i].size()>=3) r = i;
par[r] = -1;
dfs1(r,-1);
lfc = ((int)tof.size()+1)/2;
cout << lfc << '\n';
if((int)tof.size()%2==1){
int v = tof.back(), v2 = v; tof.pop_back();
while((int)adj[v].size()<=2){
dead[v] = true; v = par[v];
}
cout << v2+1 << " " << r+1 << '\n';
}
dfs(r,-1);
sort(ans.begin(), ans.end());
lfc = (int)ans.size()/2;
for(int i = 0; i < lfc; i++) cout << ans[i].second+1 << " " << ans[i+lfc].second+1 << '\n';
return 0;
}
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
8 ms |
12072 KB |
Output is correct |
| 2 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 3 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 4 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 5 |
Correct |
8 ms |
12076 KB |
Output is correct |
| 6 |
Correct |
9 ms |
11980 KB |
Output is correct |
| 7 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 8 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 9 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 10 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 11 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 12 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 13 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 14 |
Correct |
8 ms |
11964 KB |
Output is correct |
| 15 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 16 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 17 |
Correct |
7 ms |
12004 KB |
Output is correct |
| 18 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 19 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 20 |
Correct |
8 ms |
11980 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
8 ms |
12072 KB |
Output is correct |
| 2 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 3 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 4 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 5 |
Correct |
8 ms |
12076 KB |
Output is correct |
| 6 |
Correct |
9 ms |
11980 KB |
Output is correct |
| 7 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 8 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 9 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 10 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 11 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 12 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 13 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 14 |
Correct |
8 ms |
11964 KB |
Output is correct |
| 15 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 16 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 17 |
Correct |
7 ms |
12004 KB |
Output is correct |
| 18 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 19 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 20 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 21 |
Correct |
7 ms |
12040 KB |
Output is correct |
| 22 |
Correct |
8 ms |
12236 KB |
Output is correct |
| 23 |
Correct |
10 ms |
12116 KB |
Output is correct |
| 24 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 25 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 26 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 27 |
Correct |
9 ms |
12152 KB |
Output is correct |
| 28 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 29 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 30 |
Correct |
8 ms |
12068 KB |
Output is correct |
| 31 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 32 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 33 |
Correct |
7 ms |
12108 KB |
Output is correct |
| 34 |
Correct |
8 ms |
11984 KB |
Output is correct |
| 35 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 36 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 37 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 38 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 39 |
Correct |
7 ms |
12088 KB |
Output is correct |
| 40 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 41 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 42 |
Correct |
8 ms |
12088 KB |
Output is correct |
| 43 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 44 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 45 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 46 |
Correct |
8 ms |
12236 KB |
Output is correct |
| 47 |
Correct |
7 ms |
12052 KB |
Output is correct |
| 48 |
Correct |
8 ms |
11988 KB |
Output is correct |
| 49 |
Correct |
10 ms |
12108 KB |
Output is correct |
| 50 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 51 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 52 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 53 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 54 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 55 |
Correct |
8 ms |
12024 KB |
Output is correct |
| 56 |
Correct |
8 ms |
12024 KB |
Output is correct |
| 57 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 58 |
Correct |
9 ms |
12108 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
8 ms |
12072 KB |
Output is correct |
| 2 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 3 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 4 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 5 |
Correct |
8 ms |
12076 KB |
Output is correct |
| 6 |
Correct |
9 ms |
11980 KB |
Output is correct |
| 7 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 8 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 9 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 10 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 11 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 12 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 13 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 14 |
Correct |
8 ms |
11964 KB |
Output is correct |
| 15 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 16 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 17 |
Correct |
7 ms |
12004 KB |
Output is correct |
| 18 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 19 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 20 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 21 |
Correct |
7 ms |
12040 KB |
Output is correct |
| 22 |
Correct |
8 ms |
12236 KB |
Output is correct |
| 23 |
Correct |
10 ms |
12116 KB |
Output is correct |
| 24 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 25 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 26 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 27 |
Correct |
9 ms |
12152 KB |
Output is correct |
| 28 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 29 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 30 |
Correct |
8 ms |
12068 KB |
Output is correct |
| 31 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 32 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 33 |
Correct |
7 ms |
12108 KB |
Output is correct |
| 34 |
Correct |
8 ms |
11984 KB |
Output is correct |
| 35 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 36 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 37 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 38 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 39 |
Correct |
7 ms |
12088 KB |
Output is correct |
| 40 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 41 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 42 |
Correct |
8 ms |
12088 KB |
Output is correct |
| 43 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 44 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 45 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 46 |
Correct |
8 ms |
12236 KB |
Output is correct |
| 47 |
Correct |
7 ms |
12052 KB |
Output is correct |
| 48 |
Correct |
8 ms |
11988 KB |
Output is correct |
| 49 |
Correct |
10 ms |
12108 KB |
Output is correct |
| 50 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 51 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 52 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 53 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 54 |
Correct |
7 ms |
11980 KB |
Output is correct |
| 55 |
Correct |
8 ms |
12024 KB |
Output is correct |
| 56 |
Correct |
8 ms |
12024 KB |
Output is correct |
| 57 |
Correct |
8 ms |
12108 KB |
Output is correct |
| 58 |
Correct |
9 ms |
12108 KB |
Output is correct |
| 59 |
Correct |
419 ms |
35880 KB |
Output is correct |
| 60 |
Correct |
515 ms |
38756 KB |
Output is correct |
| 61 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 62 |
Correct |
8 ms |
11980 KB |
Output is correct |
| 63 |
Correct |
389 ms |
33716 KB |
Output is correct |
| 64 |
Correct |
10 ms |
12492 KB |
Output is correct |
| 65 |
Correct |
22 ms |
14264 KB |
Output is correct |
| 66 |
Correct |
169 ms |
25600 KB |
Output is correct |
| 67 |
Correct |
337 ms |
27596 KB |
Output is correct |
| 68 |
Correct |
612 ms |
53440 KB |
Output is correct |
| 69 |
Correct |
14 ms |
13120 KB |
Output is correct |
| 70 |
Correct |
98 ms |
21588 KB |
Output is correct |
| 71 |
Correct |
353 ms |
42980 KB |
Output is correct |
| 72 |
Correct |
390 ms |
41908 KB |
Output is correct |
| 73 |
Correct |
112 ms |
19124 KB |
Output is correct |
| 74 |
Correct |
537 ms |
36840 KB |
Output is correct |
| 75 |
Correct |
33 ms |
15416 KB |
Output is correct |
| 76 |
Correct |
362 ms |
42520 KB |
Output is correct |
| 77 |
Correct |
384 ms |
43164 KB |
Output is correct |
| 78 |
Correct |
36 ms |
15768 KB |
Output is correct |
| 79 |
Correct |
581 ms |
42468 KB |
Output is correct |
| 80 |
Correct |
9 ms |
12236 KB |
Output is correct |
| 81 |
Correct |
119 ms |
21532 KB |
Output is correct |
| 82 |
Correct |
453 ms |
40024 KB |
Output is correct |
| 83 |
Correct |
540 ms |
36836 KB |
Output is correct |
| 84 |
Correct |
599 ms |
36920 KB |
Output is correct |
| 85 |
Correct |
541 ms |
36908 KB |
Output is correct |
| 86 |
Correct |
523 ms |
38652 KB |
Output is correct |
| 87 |
Correct |
517 ms |
38640 KB |
Output is correct |
