# |
Submission time |
Handle |
Problem |
Language |
Result |
Execution time |
Memory |
653413 |
2022-10-26T19:01:02 Z |
pauloamed |
Network (BOI15_net) |
C++14 |
|
193 ms |
22740 KB |
#include<bits/stdc++.h>
using namespace std;
const int MAXN = 200000;
struct DSU{
int sizes[MAXN];
int parents[MAXN];
DSU(int n){
for(int i = 0; i < n; ++i){
sizes[i] = 1;
parents[i] = i;
}
}
int find(int current){
int newRoot = current;
while(newRoot != parents[newRoot]) newRoot = parents[newRoot];
// rmv if using rollback
int next;
while(parents[current] != newRoot){
next = parents[current];
parents[current] = newRoot;
}
return newRoot;
}
void onion(int a, int b){
a = find(a); b = find(b);
if(a == b) return;
if(sizes[a] < sizes[b]) swap(a,b);
sizes[a] += sizes[b];
parents[b] = a;
}
};
vector<int> v[MAXN];
vector<int> u[MAXN];
pair<int,int> deep(int x, int p){
pair<int,int> ret = {0, x};
for(auto y : v[x]) if(y != p){
ret = max(ret, deep(y, x));
}
return {ret.first + 1, ret.second};
}
bool mark(int x, int p, int target, DSU &dsu){
bool has = (x == target);
for(auto y : v[x]) if(y != p){
if(mark(y, x, target, dsu)){
dsu.onion(x, y);
return true;
}
}
return has;
}
int main(){
int n; cin >> n;
for(int i = 0; i + 1 < n; ++i){
int a, b; cin >> a >> b;
a--; b--;
v[a].push_back(b);
v[b].push_back(a);
}
DSU dsu(n);
vector<pair<int,int>> ans;
while(dsu.sizes[dsu.find(0)] != n){
int start = dsu.find(0);
auto [_, x] = deep(start, -1);
auto [__, y] = deep(x, -1);
ans.push_back({x, y});
mark(x, -1, y, dsu);
for(int i = 0; i < n; ++i){
int a = dsu.find(i);
for(auto y : v[i]){
int b = dsu.find(y);
if(a != b){
u[a].push_back(b);
u[b].push_back(a);
}
}
}
for(int i = 0; i < n; ++i) if(dsu.find(i) == i){
sort(u[i].begin(), u[i].end());
u[i].erase(unique(u[i].begin(), u[i].end()), u[i].end());
v[i].clear();
swap(v[i], u[i]);
}
}
cout << ans.size() << "\n";
for(auto [a, b] : ans) cout << a + 1 << " " << b + 1 << "\n";
}
Compilation message
net.cpp: In member function 'int DSU::find(int)':
net.cpp:22:9: warning: variable 'next' set but not used [-Wunused-but-set-variable]
22 | int next;
| ^~~~
net.cpp: In function 'int main()':
net.cpp:76:10: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
76 | auto [_, x] = deep(start, -1);
| ^
net.cpp:77:10: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
77 | auto [__, y] = deep(x, -1);
| ^
net.cpp:102:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
102 | for(auto [a, b] : ans) cout << a + 1 << " " << b + 1 << "\n";
| ^
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
11220 KB |
Output is correct |
2 |
Correct |
6 ms |
11220 KB |
Output is correct |
3 |
Correct |
7 ms |
11220 KB |
Output is correct |
4 |
Correct |
6 ms |
11220 KB |
Output is correct |
5 |
Correct |
7 ms |
11220 KB |
Output is correct |
6 |
Correct |
6 ms |
11236 KB |
Output is correct |
7 |
Correct |
6 ms |
11220 KB |
Output is correct |
8 |
Correct |
7 ms |
11256 KB |
Output is correct |
9 |
Correct |
6 ms |
11220 KB |
Output is correct |
10 |
Correct |
7 ms |
11220 KB |
Output is correct |
11 |
Correct |
7 ms |
11220 KB |
Output is correct |
12 |
Correct |
7 ms |
11252 KB |
Output is correct |
13 |
Correct |
6 ms |
11220 KB |
Output is correct |
14 |
Correct |
6 ms |
11220 KB |
Output is correct |
15 |
Correct |
6 ms |
11220 KB |
Output is correct |
16 |
Correct |
6 ms |
11220 KB |
Output is correct |
17 |
Correct |
6 ms |
11220 KB |
Output is correct |
18 |
Correct |
7 ms |
11252 KB |
Output is correct |
19 |
Correct |
7 ms |
11184 KB |
Output is correct |
20 |
Correct |
7 ms |
11164 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
11220 KB |
Output is correct |
2 |
Correct |
6 ms |
11220 KB |
Output is correct |
3 |
Correct |
7 ms |
11220 KB |
Output is correct |
4 |
Correct |
6 ms |
11220 KB |
Output is correct |
5 |
Correct |
7 ms |
11220 KB |
Output is correct |
6 |
Correct |
6 ms |
11236 KB |
Output is correct |
7 |
Correct |
6 ms |
11220 KB |
Output is correct |
8 |
Correct |
7 ms |
11256 KB |
Output is correct |
9 |
Correct |
6 ms |
11220 KB |
Output is correct |
10 |
Correct |
7 ms |
11220 KB |
Output is correct |
11 |
Correct |
7 ms |
11220 KB |
Output is correct |
12 |
Correct |
7 ms |
11252 KB |
Output is correct |
13 |
Correct |
6 ms |
11220 KB |
Output is correct |
14 |
Correct |
6 ms |
11220 KB |
Output is correct |
15 |
Correct |
6 ms |
11220 KB |
Output is correct |
16 |
Correct |
6 ms |
11220 KB |
Output is correct |
17 |
Correct |
6 ms |
11220 KB |
Output is correct |
18 |
Correct |
7 ms |
11252 KB |
Output is correct |
19 |
Correct |
7 ms |
11184 KB |
Output is correct |
20 |
Correct |
7 ms |
11164 KB |
Output is correct |
21 |
Correct |
7 ms |
11220 KB |
Output is correct |
22 |
Correct |
170 ms |
11480 KB |
Output is correct |
23 |
Correct |
184 ms |
11496 KB |
Output is correct |
24 |
Correct |
130 ms |
11552 KB |
Output is correct |
25 |
Correct |
84 ms |
11420 KB |
Output is correct |
26 |
Correct |
64 ms |
11420 KB |
Output is correct |
27 |
Correct |
118 ms |
11508 KB |
Output is correct |
28 |
Correct |
101 ms |
11604 KB |
Output is correct |
29 |
Correct |
63 ms |
11348 KB |
Output is correct |
30 |
Correct |
8 ms |
11220 KB |
Output is correct |
31 |
Correct |
126 ms |
11488 KB |
Output is correct |
32 |
Correct |
6 ms |
11260 KB |
Output is correct |
33 |
Correct |
7 ms |
11220 KB |
Output is correct |
34 |
Correct |
6 ms |
11220 KB |
Output is correct |
35 |
Correct |
7 ms |
11260 KB |
Output is correct |
36 |
Correct |
6 ms |
11260 KB |
Output is correct |
37 |
Correct |
7 ms |
11260 KB |
Output is correct |
38 |
Correct |
7 ms |
11348 KB |
Output is correct |
39 |
Correct |
7 ms |
11256 KB |
Output is correct |
40 |
Correct |
6 ms |
11220 KB |
Output is correct |
41 |
Correct |
7 ms |
11248 KB |
Output is correct |
42 |
Correct |
17 ms |
11316 KB |
Output is correct |
43 |
Correct |
52 ms |
11356 KB |
Output is correct |
44 |
Correct |
6 ms |
11220 KB |
Output is correct |
45 |
Correct |
9 ms |
11220 KB |
Output is correct |
46 |
Correct |
24 ms |
11292 KB |
Output is correct |
47 |
Correct |
6 ms |
11220 KB |
Output is correct |
48 |
Correct |
10 ms |
11224 KB |
Output is correct |
49 |
Correct |
57 ms |
11348 KB |
Output is correct |
50 |
Correct |
7 ms |
11220 KB |
Output is correct |
51 |
Correct |
6 ms |
11256 KB |
Output is correct |
52 |
Correct |
8 ms |
11220 KB |
Output is correct |
53 |
Correct |
14 ms |
11348 KB |
Output is correct |
54 |
Correct |
6 ms |
11256 KB |
Output is correct |
55 |
Correct |
11 ms |
11220 KB |
Output is correct |
56 |
Correct |
7 ms |
11220 KB |
Output is correct |
57 |
Correct |
16 ms |
11220 KB |
Output is correct |
58 |
Correct |
193 ms |
11504 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
6 ms |
11220 KB |
Output is correct |
2 |
Correct |
6 ms |
11220 KB |
Output is correct |
3 |
Correct |
7 ms |
11220 KB |
Output is correct |
4 |
Correct |
6 ms |
11220 KB |
Output is correct |
5 |
Correct |
7 ms |
11220 KB |
Output is correct |
6 |
Correct |
6 ms |
11236 KB |
Output is correct |
7 |
Correct |
6 ms |
11220 KB |
Output is correct |
8 |
Correct |
7 ms |
11256 KB |
Output is correct |
9 |
Correct |
6 ms |
11220 KB |
Output is correct |
10 |
Correct |
7 ms |
11220 KB |
Output is correct |
11 |
Correct |
7 ms |
11220 KB |
Output is correct |
12 |
Correct |
7 ms |
11252 KB |
Output is correct |
13 |
Correct |
6 ms |
11220 KB |
Output is correct |
14 |
Correct |
6 ms |
11220 KB |
Output is correct |
15 |
Correct |
6 ms |
11220 KB |
Output is correct |
16 |
Correct |
6 ms |
11220 KB |
Output is correct |
17 |
Correct |
6 ms |
11220 KB |
Output is correct |
18 |
Correct |
7 ms |
11252 KB |
Output is correct |
19 |
Correct |
7 ms |
11184 KB |
Output is correct |
20 |
Correct |
7 ms |
11164 KB |
Output is correct |
21 |
Correct |
7 ms |
11220 KB |
Output is correct |
22 |
Correct |
170 ms |
11480 KB |
Output is correct |
23 |
Correct |
184 ms |
11496 KB |
Output is correct |
24 |
Correct |
130 ms |
11552 KB |
Output is correct |
25 |
Correct |
84 ms |
11420 KB |
Output is correct |
26 |
Correct |
64 ms |
11420 KB |
Output is correct |
27 |
Correct |
118 ms |
11508 KB |
Output is correct |
28 |
Correct |
101 ms |
11604 KB |
Output is correct |
29 |
Correct |
63 ms |
11348 KB |
Output is correct |
30 |
Correct |
8 ms |
11220 KB |
Output is correct |
31 |
Correct |
126 ms |
11488 KB |
Output is correct |
32 |
Correct |
6 ms |
11260 KB |
Output is correct |
33 |
Correct |
7 ms |
11220 KB |
Output is correct |
34 |
Correct |
6 ms |
11220 KB |
Output is correct |
35 |
Correct |
7 ms |
11260 KB |
Output is correct |
36 |
Correct |
6 ms |
11260 KB |
Output is correct |
37 |
Correct |
7 ms |
11260 KB |
Output is correct |
38 |
Correct |
7 ms |
11348 KB |
Output is correct |
39 |
Correct |
7 ms |
11256 KB |
Output is correct |
40 |
Correct |
6 ms |
11220 KB |
Output is correct |
41 |
Correct |
7 ms |
11248 KB |
Output is correct |
42 |
Correct |
17 ms |
11316 KB |
Output is correct |
43 |
Correct |
52 ms |
11356 KB |
Output is correct |
44 |
Correct |
6 ms |
11220 KB |
Output is correct |
45 |
Correct |
9 ms |
11220 KB |
Output is correct |
46 |
Correct |
24 ms |
11292 KB |
Output is correct |
47 |
Correct |
6 ms |
11220 KB |
Output is correct |
48 |
Correct |
10 ms |
11224 KB |
Output is correct |
49 |
Correct |
57 ms |
11348 KB |
Output is correct |
50 |
Correct |
7 ms |
11220 KB |
Output is correct |
51 |
Correct |
6 ms |
11256 KB |
Output is correct |
52 |
Correct |
8 ms |
11220 KB |
Output is correct |
53 |
Correct |
14 ms |
11348 KB |
Output is correct |
54 |
Correct |
6 ms |
11256 KB |
Output is correct |
55 |
Correct |
11 ms |
11220 KB |
Output is correct |
56 |
Correct |
7 ms |
11220 KB |
Output is correct |
57 |
Correct |
16 ms |
11220 KB |
Output is correct |
58 |
Correct |
193 ms |
11504 KB |
Output is correct |
59 |
Runtime error |
15 ms |
22740 KB |
Execution killed with signal 11 |
60 |
Halted |
0 ms |
0 KB |
- |