#include <bits/stdc++.h>
#include <iomanip>
#define ll long long
#define pb push_back
#define F first
#define S second
#define nl '\n'
#define all(x) x.begin(), x.end()
const int N = 5e5 + 7;
const int modd = 1e9 + 7;
const int INF = 1e9 + 7;
const double pi = 3.141592653589793238462643383279502884197;
const double EPS = 0.0000000000001;
using namespace std;
int gcd(int a, int b){
if (b == 0)
return a;
else
return gcd(b, a % b);
}
ll binpow(ll a, ll x){
if(x == 0) return 1;
if(x % 2 == 0){
ll y = binpow(a, x / 2);
return (y * y);
}
else{
return (binpow(a, x - 1) * a);
}
}
ll n;
vector <ll> v[N];
vector <ll> s;
vector <ll> l;
vector <ll> r;
bool used[N];
void dfs(ll x){
used[x] = 1;
if(v[x].size() == 1){
s.pb(x);
}
for(auto to : v[x]){
if(used[to] == 0){
dfs(to);
}
}
}
void Muqaltin(){
cin >> n;
for(int i = 1; i < n; i++){
int x, y;
cin >> x >> y;
v[x].pb(y);
v[y].pb(x);
}
dfs(1);
for(int i = 0; i < s.size() / 2; i++){
l.pb(s[i]);
}
for(int i = s.size() / 2; i < s.size(); i++){
r.pb(s[i]);
}
cout << max(l.size(), r.size()) << nl;
for(int i = 0; i < min(l.size(), r.size()); i++){
cout << l[i] << ' ' << r[i] << nl;
}
if(l.size() > r.size()){
cout << l[l.size() - 1] << " " << l[0] << nl;
}
else if(l.size() < r.size()){
cout << r[r.size() - 1] << " " << r[0] << nl;
}
return;
}
int main(){
// freopen("pails.in", "r", stdin);
// freopen("pails.out", "w", stdout);
ios_base :: sync_with_stdio(0);
cin.tie(0), cout.tie(0);
int t = 1;
// cin >> t;
while(t--){
Muqaltin();
}
return 0;
}
Compilation message
net.cpp: In function 'void Muqaltin()':
net.cpp:65:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
65 | for(int i = 0; i < s.size() / 2; i++){
| ~~^~~~~~~~~~~~~~
net.cpp:68:33: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
68 | for(int i = s.size() / 2; i < s.size(); i++){
| ~~^~~~~~~~~~
net.cpp:72:22: warning: comparison of integer expressions of different signedness: 'int' and 'const long unsigned int' [-Wsign-compare]
72 | for(int i = 0; i < min(l.size(), r.size()); i++){
| ~~^~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
11988 KB |
Output is correct |
2 |
Correct |
6 ms |
11988 KB |
Output is correct |
3 |
Correct |
5 ms |
11988 KB |
Output is correct |
4 |
Correct |
5 ms |
12048 KB |
Output is correct |
5 |
Correct |
6 ms |
12072 KB |
Output is correct |
6 |
Correct |
6 ms |
12068 KB |
Output is correct |
7 |
Correct |
6 ms |
11988 KB |
Output is correct |
8 |
Correct |
8 ms |
12104 KB |
Output is correct |
9 |
Correct |
6 ms |
11988 KB |
Output is correct |
10 |
Correct |
6 ms |
11956 KB |
Output is correct |
11 |
Correct |
6 ms |
11968 KB |
Output is correct |
12 |
Correct |
5 ms |
11948 KB |
Output is correct |
13 |
Correct |
6 ms |
11988 KB |
Output is correct |
14 |
Correct |
6 ms |
11988 KB |
Output is correct |
15 |
Correct |
5 ms |
11988 KB |
Output is correct |
16 |
Correct |
6 ms |
12068 KB |
Output is correct |
17 |
Correct |
6 ms |
12072 KB |
Output is correct |
18 |
Correct |
7 ms |
12020 KB |
Output is correct |
19 |
Correct |
6 ms |
11988 KB |
Output is correct |
20 |
Correct |
6 ms |
12064 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
11988 KB |
Output is correct |
2 |
Correct |
6 ms |
11988 KB |
Output is correct |
3 |
Correct |
5 ms |
11988 KB |
Output is correct |
4 |
Correct |
5 ms |
12048 KB |
Output is correct |
5 |
Correct |
6 ms |
12072 KB |
Output is correct |
6 |
Correct |
6 ms |
12068 KB |
Output is correct |
7 |
Correct |
6 ms |
11988 KB |
Output is correct |
8 |
Correct |
8 ms |
12104 KB |
Output is correct |
9 |
Correct |
6 ms |
11988 KB |
Output is correct |
10 |
Correct |
6 ms |
11956 KB |
Output is correct |
11 |
Correct |
6 ms |
11968 KB |
Output is correct |
12 |
Correct |
5 ms |
11948 KB |
Output is correct |
13 |
Correct |
6 ms |
11988 KB |
Output is correct |
14 |
Correct |
6 ms |
11988 KB |
Output is correct |
15 |
Correct |
5 ms |
11988 KB |
Output is correct |
16 |
Correct |
6 ms |
12068 KB |
Output is correct |
17 |
Correct |
6 ms |
12072 KB |
Output is correct |
18 |
Correct |
7 ms |
12020 KB |
Output is correct |
19 |
Correct |
6 ms |
11988 KB |
Output is correct |
20 |
Correct |
6 ms |
12064 KB |
Output is correct |
21 |
Correct |
5 ms |
11988 KB |
Output is correct |
22 |
Correct |
7 ms |
12116 KB |
Output is correct |
23 |
Correct |
6 ms |
12180 KB |
Output is correct |
24 |
Correct |
6 ms |
12116 KB |
Output is correct |
25 |
Correct |
7 ms |
12264 KB |
Output is correct |
26 |
Correct |
6 ms |
12104 KB |
Output is correct |
27 |
Correct |
6 ms |
12116 KB |
Output is correct |
28 |
Correct |
6 ms |
12116 KB |
Output is correct |
29 |
Correct |
6 ms |
12116 KB |
Output is correct |
30 |
Correct |
6 ms |
12068 KB |
Output is correct |
31 |
Correct |
8 ms |
12220 KB |
Output is correct |
32 |
Correct |
5 ms |
11988 KB |
Output is correct |
33 |
Correct |
6 ms |
12052 KB |
Output is correct |
34 |
Correct |
6 ms |
11988 KB |
Output is correct |
35 |
Correct |
6 ms |
11988 KB |
Output is correct |
36 |
Correct |
6 ms |
11988 KB |
Output is correct |
37 |
Correct |
6 ms |
11988 KB |
Output is correct |
38 |
Correct |
6 ms |
12076 KB |
Output is correct |
39 |
Correct |
7 ms |
11988 KB |
Output is correct |
40 |
Correct |
7 ms |
11988 KB |
Output is correct |
41 |
Correct |
6 ms |
11988 KB |
Output is correct |
42 |
Correct |
6 ms |
11996 KB |
Output is correct |
43 |
Correct |
7 ms |
12076 KB |
Output is correct |
44 |
Correct |
6 ms |
11988 KB |
Output is correct |
45 |
Correct |
6 ms |
11988 KB |
Output is correct |
46 |
Correct |
6 ms |
12068 KB |
Output is correct |
47 |
Correct |
6 ms |
12000 KB |
Output is correct |
48 |
Correct |
6 ms |
11988 KB |
Output is correct |
49 |
Correct |
6 ms |
12080 KB |
Output is correct |
50 |
Correct |
6 ms |
11988 KB |
Output is correct |
51 |
Correct |
5 ms |
12076 KB |
Output is correct |
52 |
Correct |
7 ms |
11988 KB |
Output is correct |
53 |
Correct |
6 ms |
12116 KB |
Output is correct |
54 |
Correct |
6 ms |
11988 KB |
Output is correct |
55 |
Correct |
6 ms |
11988 KB |
Output is correct |
56 |
Correct |
7 ms |
11988 KB |
Output is correct |
57 |
Correct |
6 ms |
11988 KB |
Output is correct |
58 |
Correct |
6 ms |
12204 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
6 ms |
11988 KB |
Output is correct |
2 |
Correct |
6 ms |
11988 KB |
Output is correct |
3 |
Correct |
5 ms |
11988 KB |
Output is correct |
4 |
Correct |
5 ms |
12048 KB |
Output is correct |
5 |
Correct |
6 ms |
12072 KB |
Output is correct |
6 |
Correct |
6 ms |
12068 KB |
Output is correct |
7 |
Correct |
6 ms |
11988 KB |
Output is correct |
8 |
Correct |
8 ms |
12104 KB |
Output is correct |
9 |
Correct |
6 ms |
11988 KB |
Output is correct |
10 |
Correct |
6 ms |
11956 KB |
Output is correct |
11 |
Correct |
6 ms |
11968 KB |
Output is correct |
12 |
Correct |
5 ms |
11948 KB |
Output is correct |
13 |
Correct |
6 ms |
11988 KB |
Output is correct |
14 |
Correct |
6 ms |
11988 KB |
Output is correct |
15 |
Correct |
5 ms |
11988 KB |
Output is correct |
16 |
Correct |
6 ms |
12068 KB |
Output is correct |
17 |
Correct |
6 ms |
12072 KB |
Output is correct |
18 |
Correct |
7 ms |
12020 KB |
Output is correct |
19 |
Correct |
6 ms |
11988 KB |
Output is correct |
20 |
Correct |
6 ms |
12064 KB |
Output is correct |
21 |
Correct |
5 ms |
11988 KB |
Output is correct |
22 |
Correct |
7 ms |
12116 KB |
Output is correct |
23 |
Correct |
6 ms |
12180 KB |
Output is correct |
24 |
Correct |
6 ms |
12116 KB |
Output is correct |
25 |
Correct |
7 ms |
12264 KB |
Output is correct |
26 |
Correct |
6 ms |
12104 KB |
Output is correct |
27 |
Correct |
6 ms |
12116 KB |
Output is correct |
28 |
Correct |
6 ms |
12116 KB |
Output is correct |
29 |
Correct |
6 ms |
12116 KB |
Output is correct |
30 |
Correct |
6 ms |
12068 KB |
Output is correct |
31 |
Correct |
8 ms |
12220 KB |
Output is correct |
32 |
Correct |
5 ms |
11988 KB |
Output is correct |
33 |
Correct |
6 ms |
12052 KB |
Output is correct |
34 |
Correct |
6 ms |
11988 KB |
Output is correct |
35 |
Correct |
6 ms |
11988 KB |
Output is correct |
36 |
Correct |
6 ms |
11988 KB |
Output is correct |
37 |
Correct |
6 ms |
11988 KB |
Output is correct |
38 |
Correct |
6 ms |
12076 KB |
Output is correct |
39 |
Correct |
7 ms |
11988 KB |
Output is correct |
40 |
Correct |
7 ms |
11988 KB |
Output is correct |
41 |
Correct |
6 ms |
11988 KB |
Output is correct |
42 |
Correct |
6 ms |
11996 KB |
Output is correct |
43 |
Correct |
7 ms |
12076 KB |
Output is correct |
44 |
Correct |
6 ms |
11988 KB |
Output is correct |
45 |
Correct |
6 ms |
11988 KB |
Output is correct |
46 |
Correct |
6 ms |
12068 KB |
Output is correct |
47 |
Correct |
6 ms |
12000 KB |
Output is correct |
48 |
Correct |
6 ms |
11988 KB |
Output is correct |
49 |
Correct |
6 ms |
12080 KB |
Output is correct |
50 |
Correct |
6 ms |
11988 KB |
Output is correct |
51 |
Correct |
5 ms |
12076 KB |
Output is correct |
52 |
Correct |
7 ms |
11988 KB |
Output is correct |
53 |
Correct |
6 ms |
12116 KB |
Output is correct |
54 |
Correct |
6 ms |
11988 KB |
Output is correct |
55 |
Correct |
6 ms |
11988 KB |
Output is correct |
56 |
Correct |
7 ms |
11988 KB |
Output is correct |
57 |
Correct |
6 ms |
11988 KB |
Output is correct |
58 |
Correct |
6 ms |
12204 KB |
Output is correct |
59 |
Correct |
235 ms |
45268 KB |
Output is correct |
60 |
Correct |
302 ms |
48388 KB |
Output is correct |
61 |
Correct |
6 ms |
11988 KB |
Output is correct |
62 |
Correct |
6 ms |
11988 KB |
Output is correct |
63 |
Correct |
200 ms |
41340 KB |
Output is correct |
64 |
Correct |
9 ms |
12460 KB |
Output is correct |
65 |
Correct |
13 ms |
13908 KB |
Output is correct |
66 |
Correct |
98 ms |
28084 KB |
Output is correct |
67 |
Correct |
325 ms |
47344 KB |
Output is correct |
68 |
Correct |
371 ms |
49444 KB |
Output is correct |
69 |
Correct |
10 ms |
13104 KB |
Output is correct |
70 |
Correct |
55 ms |
24528 KB |
Output is correct |
71 |
Correct |
189 ms |
52068 KB |
Output is correct |
72 |
Correct |
202 ms |
50220 KB |
Output is correct |
73 |
Correct |
52 ms |
21056 KB |
Output is correct |
74 |
Correct |
306 ms |
44452 KB |
Output is correct |
75 |
Correct |
23 ms |
16204 KB |
Output is correct |
76 |
Correct |
239 ms |
51516 KB |
Output is correct |
77 |
Correct |
226 ms |
51936 KB |
Output is correct |
78 |
Correct |
21 ms |
15700 KB |
Output is correct |
79 |
Correct |
341 ms |
45644 KB |
Output is correct |
80 |
Correct |
7 ms |
12244 KB |
Output is correct |
81 |
Correct |
63 ms |
24064 KB |
Output is correct |
82 |
Correct |
282 ms |
48560 KB |
Output is correct |
83 |
Correct |
289 ms |
44464 KB |
Output is correct |
84 |
Correct |
288 ms |
44632 KB |
Output is correct |
85 |
Correct |
305 ms |
44436 KB |
Output is correct |
86 |
Correct |
313 ms |
48560 KB |
Output is correct |
87 |
Correct |
328 ms |
48356 KB |
Output is correct |