| # |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
| 22984 |
2017-05-01T02:38:28 Z |
model_code |
Network (BOI15_net) |
C++11 |
|
846 ms |
52032 KB |
// Kamil Debowski
// AC solution
#include<cstdio>
#include<vector>
#include<algorithm>
#include<assert.h>
using namespace std;
const int nax = 5e5 + 5;
vector<int> w[nax];
int leaves[nax];
void dfs_first(int a, int father) {
for(int i = 0; i < (int) w[a].size(); ++i) {
int b = w[a][i];
if(b == father) {
w[a].erase(w[a].begin() + i);
--i;
}
else {
dfs_first(b, a);
leaves[a] += leaves[b];
}
}
if(w[a].empty()) leaves[a] = 1;
}
void give_leaves(int a, vector<int> & vec) {
for(auto b : w[a])
give_leaves(b, vec);
if(w[a].empty()) // leaf
vec.push_back(a);
}
vector<int> sets[3];
int half;
bool cmp(const vector<int> & a, const vector<int> & b) { return a.size() > b.size(); }
void dfs(int a) {
int big = 0;
for(auto b : w[a])
if(leaves[b] > leaves[big])
big = b;
if(leaves[big] > half) {
for(auto b : w[a])
if(b != big)
give_leaves(b, sets[0]);
dfs(big);
return;
}
for(auto b : w[a])
for(int i = 0; i < 3; ++i)
if(leaves[b] + (int) sets[i].size() <= half) {
give_leaves(b, sets[i]);
break;
}
for(int i = 0; i < half; ++i) {
sort(sets, sets + 3, cmp);
printf("%d %d\n", sets[0].back(), sets[1].back());
sets[0].pop_back();
sets[1].pop_back();
}
sort(sets, sets + 3, cmp);
if(!sets[0].empty())
printf("%d %d\n", a, sets[0].back());
}
int main()
{
int n;
scanf("%d", &n);
if(n == 1) {
puts("0");
return 0;
}
if(n == 2) {
puts("1");
puts("1 2");
return 0;
}
for(int i = 0; i < n - 1; ++i) {
int a, b;
scanf("%d%d", &a, &b);
w[a].push_back(b);
w[b].push_back(a);
}
int root = 1;
while((int) w[root].size() < 2) root++;
dfs_first(root, 0);
half = leaves[root] / 2;
printf("%d\n", (leaves[root] + 1) / 2);
dfs(root);
return 0;
}
Compilation message
net.cpp: In function 'int main()':
net.cpp:72:17: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d", &n);
^
net.cpp:84:24: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &a, &b);
^
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 2 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 3 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 4 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 5 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 6 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 7 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 8 |
Correct |
6 ms |
14848 KB |
Output is correct |
| 9 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 10 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 11 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 12 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 13 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 14 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 15 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 16 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 17 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 18 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 19 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 20 |
Correct |
0 ms |
14848 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 2 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 3 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 4 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 5 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 6 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 7 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 8 |
Correct |
6 ms |
14848 KB |
Output is correct |
| 9 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 10 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 11 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 12 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 13 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 14 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 15 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 16 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 17 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 18 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 19 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 20 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 21 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 22 |
Correct |
3 ms |
14980 KB |
Output is correct |
| 23 |
Correct |
3 ms |
14980 KB |
Output is correct |
| 24 |
Correct |
0 ms |
14980 KB |
Output is correct |
| 25 |
Correct |
3 ms |
14980 KB |
Output is correct |
| 26 |
Correct |
3 ms |
14980 KB |
Output is correct |
| 27 |
Correct |
3 ms |
14980 KB |
Output is correct |
| 28 |
Correct |
3 ms |
14980 KB |
Output is correct |
| 29 |
Correct |
0 ms |
14980 KB |
Output is correct |
| 30 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 31 |
Correct |
3 ms |
14980 KB |
Output is correct |
| 32 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 33 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 34 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 35 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 36 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 37 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 38 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 39 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 40 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 41 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 42 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 43 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 44 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 45 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 46 |
Correct |
6 ms |
14848 KB |
Output is correct |
| 47 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 48 |
Correct |
9 ms |
14848 KB |
Output is correct |
| 49 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 50 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 51 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 52 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 53 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 54 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 55 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 56 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 57 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 58 |
Correct |
3 ms |
14980 KB |
Output is correct |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 2 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 3 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 4 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 5 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 6 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 7 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 8 |
Correct |
6 ms |
14848 KB |
Output is correct |
| 9 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 10 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 11 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 12 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 13 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 14 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 15 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 16 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 17 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 18 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 19 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 20 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 21 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 22 |
Correct |
3 ms |
14980 KB |
Output is correct |
| 23 |
Correct |
3 ms |
14980 KB |
Output is correct |
| 24 |
Correct |
0 ms |
14980 KB |
Output is correct |
| 25 |
Correct |
3 ms |
14980 KB |
Output is correct |
| 26 |
Correct |
3 ms |
14980 KB |
Output is correct |
| 27 |
Correct |
3 ms |
14980 KB |
Output is correct |
| 28 |
Correct |
3 ms |
14980 KB |
Output is correct |
| 29 |
Correct |
0 ms |
14980 KB |
Output is correct |
| 30 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 31 |
Correct |
3 ms |
14980 KB |
Output is correct |
| 32 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 33 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 34 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 35 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 36 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 37 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 38 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 39 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 40 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 41 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 42 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 43 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 44 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 45 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 46 |
Correct |
6 ms |
14848 KB |
Output is correct |
| 47 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 48 |
Correct |
9 ms |
14848 KB |
Output is correct |
| 49 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 50 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 51 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 52 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 53 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 54 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 55 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 56 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 57 |
Correct |
3 ms |
14848 KB |
Output is correct |
| 58 |
Correct |
3 ms |
14980 KB |
Output is correct |
| 59 |
Correct |
536 ms |
33100 KB |
Output is correct |
| 60 |
Correct |
609 ms |
34364 KB |
Output is correct |
| 61 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 62 |
Correct |
0 ms |
14848 KB |
Output is correct |
| 63 |
Correct |
489 ms |
31024 KB |
Output is correct |
| 64 |
Correct |
3 ms |
15240 KB |
Output is correct |
| 65 |
Correct |
19 ms |
16932 KB |
Output is correct |
| 66 |
Correct |
236 ms |
33668 KB |
Output is correct |
| 67 |
Correct |
829 ms |
51240 KB |
Output is correct |
| 68 |
Correct |
846 ms |
52032 KB |
Output is correct |
| 69 |
Correct |
13 ms |
15556 KB |
Output is correct |
| 70 |
Correct |
113 ms |
22492 KB |
Output is correct |
| 71 |
Correct |
396 ms |
35676 KB |
Output is correct |
| 72 |
Correct |
466 ms |
35676 KB |
Output is correct |
| 73 |
Correct |
133 ms |
20208 KB |
Output is correct |
| 74 |
Correct |
673 ms |
32648 KB |
Output is correct |
| 75 |
Correct |
26 ms |
17188 KB |
Output is correct |
| 76 |
Correct |
433 ms |
35688 KB |
Output is correct |
| 77 |
Correct |
439 ms |
35688 KB |
Output is correct |
| 78 |
Correct |
36 ms |
18152 KB |
Output is correct |
| 79 |
Correct |
786 ms |
48340 KB |
Output is correct |
| 80 |
Correct |
6 ms |
14980 KB |
Output is correct |
| 81 |
Correct |
159 ms |
21620 KB |
Output is correct |
| 82 |
Correct |
533 ms |
34932 KB |
Output is correct |
| 83 |
Correct |
646 ms |
32904 KB |
Output is correct |
| 84 |
Correct |
646 ms |
32648 KB |
Output is correct |
| 85 |
Correct |
656 ms |
33164 KB |
Output is correct |
| 86 |
Correct |
606 ms |
33860 KB |
Output is correct |
| 87 |
Correct |
643 ms |
34368 KB |
Output is correct |
