#include <bits/stdc++.h>
using namespace std;
int n, m;
typedef vector<int> vi;
typedef pair<int,int> ii;
struct node{
int depth = -1;
int low;
int parent;
bool vis = false;
bool isArti = false;
vi adj;
};
vector<unordered_set<int> > biconnected;
stack<int> s; ///this is only needed for biconnected components
///note: this will ignore single nodes with no edges
static node g[200005];
int rootChildren = 0;
void dfs(int u){
if(g[u].depth == -1) g[u].depth = g[g[u].parent].depth + 1;
g[u].low = g[u].depth;
g[u].vis = true;
for(int i = 0;i < g[u].adj.size();i++){
int v = g[u].adj[i];
if(!g[v].vis){
g[v].parent = u;
if(g[u].depth == 0) rootChildren++;
s.push(u); ///s traces the path of tree traversal
dfs(v);
g[u].low = min(g[u].low,g[v].low);
if(g[v].low >= g[u].depth){
g[u].isArti = true;
g[u].low = min(g[u].low,g[v].low);
unordered_set<int> newSet;
int nn;
biconnected.push_back(newSet); ///create new biconnected component
do{
assert(!s.empty());
nn = s.top();
s.pop();
biconnected.back().insert(nn);
}while(nn != u);
}
///if(g[v].low > g[u].depth{
///u,v is a bridge
///}
}
else if(v != g[u].parent){
g[u].low = min(g[u].low,g[v].low);
}
s.push(u);
}
}
struct node2{
long long sz;
long long dp = 0;
bool isArti = false;
bool vis = false;
int r;
int p = -1;
vi adj;
};
vector<node2> bct; ///block-cut tree
long long root = -1;
void dp(int u){
if(bct[u].vis) return;
bct[u].vis = true;
bct[u].dp = bct[u].sz;
bct[u].r = root;
for(int i = 0;i < bct[u].adj.size();i++){
int v = bct[u].adj[i];
if(bct[v].vis) continue;
bct[v].p = u;
dp(v);
bct[u].dp += bct[v].dp;
}
}
int main()
{
//freopen("i.txt","r",stdin);
cin >> n >> m;
ii edges[m];
for(int i = 0;i < m;i++){
int a, b;
cin >> a >> b;
a--;
b--;
g[a].adj.push_back(b);
g[b].adj.push_back(a);
edges[i] = ii(a,b);
}
for(int i = 0;i < n;i++){
if(!g[i].vis){
rootChildren = 0;
g[i].depth = 0;
dfs(i);
if(rootChildren > 1) g[i].isArti = true;
else g[i].isArti = false; ///this line is needed
}
}
unordered_map<int,int> artis;
for(int i = 0;i < n;i++){
if(g[i].isArti){
artis[i] = bct.size();
node2 nn;
nn.sz = 1;
nn.isArti = true;
bct.push_back(nn);
}
}
for(int i = 0;i < biconnected.size();i++){
node2 nn;
nn.sz = biconnected[i].size();
nn.isArti = false;
for(unordered_set<int>::iterator it = biconnected[i].begin();it != biconnected[i].end();it++){
//cout << *it << " ";
if(artis.find(*it) != artis.end()){
nn.adj.push_back(artis[*it]);
bct[artis[*it]].adj.push_back(bct.size());
nn.sz--;
}
}
bct.push_back(nn);
//cout << "\n";
}
for(int i = 0;i < bct.size();i++){
root = i;
dp(i);
}
/*
for(int i = 0;i < bct.size();i++){
cout << i << " " << bct[i].sz << " " << bct[i].dp << " " << bct[i].isArti << "| ";
for(int j = 0;j < bct[i].adj.size();j++){
cout << bct[i].adj[j] << " ";
}
cout << "\n";
}
*/
long long ans = 0ll;
for(int i = 0;i < bct.size();i++){
vector<long long> branches;
vector<long long> branchStart;
long long total = 0ll;
for(int j = 0;j < bct[i].adj.size();j++){
if(bct[i].adj[j] != bct[i].p){
branches.push_back(bct[bct[i].adj[j]].dp);
branchStart.push_back(bct[bct[i].adj[j]].sz);
}
}
if(bct[i].p >= 0){
branches.push_back(bct[bct[i].r].dp - bct[i].dp);
branchStart.push_back(bct[bct[i].p].sz);
}
for(int j = 0;j < branches.size();j++) total += branches[j];
long long extra = 0ll;
if(!bct[i].isArti) extra = max(0ll,(long long)(bct[i].adj.size())-2);
for(int j = 0;j < branches.size();j++){
//cout << i << " " << branches[j] << "\n";
///branch1 to self or neighbor articulation point to branch2
ans += branches[j] * (total - branches[j]) * (bct[i].sz + extra);
///branch to self to self or self to self to branch
ans += 2 * (bct[i].sz) * (bct[i].sz - 1) * branches[j];
///self to arti to another branch
//if(!bct[i].isArti){
// ans += 2ll * (bct[i].sz) * branches[j] * (bct[i].adj.size() - 1);
//}
if(bct[i].isArti){
///direct branch to self to same branch(not reverse) or its reverse
ans += 2ll * bct[i].sz * branchStart[j] * (branches[j] - branchStart[j]);
///direct branch to self to direct or its reverse
ans += bct[i].sz * (branchStart[j]) * (branchStart[j] - 1);
}
}
///self to self to self
ans += (bct[i].sz) * (bct[i].sz - 1) * (bct[i].sz - 2);
//if(!bct[i].isArti) ans += (bct[i].sz) * (bct[i].sz - 1) * (bct[i].adj.size());
//cout << i << " " << ans << "\n";
}
cout << ans;
}
/*
8 7
8 5
8 1
7 5
8 6
3 1
3 2
8 3
*/
/*
10 12
6 4
10 3
4 2
4 1
4 3
6 5
9 1
9 4
2 1
9 3
8 5
7 2
*/
Compilation message
count_triplets.cpp: In function 'void dfs(int)':
count_triplets.cpp:25:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 0;i < g[u].adj.size();i++){
~~^~~~~~~~~~~~~~~~~
count_triplets.cpp: In function 'void dp(int)':
count_triplets.cpp:74:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 0;i < bct[u].adj.size();i++){
~~^~~~~~~~~~~~~~~~~~~
count_triplets.cpp: In function 'int main()':
count_triplets.cpp:118:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 0;i < biconnected.size();i++){
~~^~~~~~~~~~~~~~~~~~~~
count_triplets.cpp:133:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 0;i < bct.size();i++){
~~^~~~~~~~~~~~
count_triplets.cpp:147:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i = 0;i < bct.size();i++){
~~^~~~~~~~~~~~
count_triplets.cpp:151:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int j = 0;j < bct[i].adj.size();j++){
~~^~~~~~~~~~~~~~~~~~~
count_triplets.cpp:161:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int j = 0;j < branches.size();j++) total += branches[j];
~~^~~~~~~~~~~~~~~~~
count_triplets.cpp:164:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int j = 0;j < branches.size();j++){
~~^~~~~~~~~~~~~~~~~
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
10 ms |
8192 KB |
Output is correct |
2 |
Correct |
10 ms |
8192 KB |
Output is correct |
3 |
Correct |
9 ms |
8192 KB |
Output is correct |
4 |
Correct |
10 ms |
8192 KB |
Output is correct |
5 |
Correct |
11 ms |
8192 KB |
Output is correct |
6 |
Correct |
10 ms |
8192 KB |
Output is correct |
7 |
Correct |
10 ms |
8192 KB |
Output is correct |
8 |
Correct |
11 ms |
8192 KB |
Output is correct |
9 |
Correct |
9 ms |
8192 KB |
Output is correct |
10 |
Correct |
9 ms |
8192 KB |
Output is correct |
11 |
Correct |
10 ms |
8192 KB |
Output is correct |
12 |
Correct |
10 ms |
8192 KB |
Output is correct |
13 |
Correct |
8 ms |
8192 KB |
Output is correct |
14 |
Correct |
11 ms |
8192 KB |
Output is correct |
15 |
Correct |
9 ms |
8192 KB |
Output is correct |
16 |
Correct |
12 ms |
8164 KB |
Output is correct |
17 |
Correct |
12 ms |
8192 KB |
Output is correct |
18 |
Correct |
9 ms |
8192 KB |
Output is correct |
19 |
Correct |
13 ms |
8192 KB |
Output is correct |
20 |
Correct |
10 ms |
8192 KB |
Output is correct |
21 |
Correct |
10 ms |
8192 KB |
Output is correct |
22 |
Incorrect |
11 ms |
8192 KB |
Output isn't correct |
23 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
10 ms |
8192 KB |
Output is correct |
2 |
Correct |
10 ms |
8192 KB |
Output is correct |
3 |
Correct |
9 ms |
8192 KB |
Output is correct |
4 |
Correct |
10 ms |
8192 KB |
Output is correct |
5 |
Correct |
11 ms |
8192 KB |
Output is correct |
6 |
Correct |
10 ms |
8192 KB |
Output is correct |
7 |
Correct |
10 ms |
8192 KB |
Output is correct |
8 |
Correct |
11 ms |
8192 KB |
Output is correct |
9 |
Correct |
9 ms |
8192 KB |
Output is correct |
10 |
Correct |
9 ms |
8192 KB |
Output is correct |
11 |
Correct |
10 ms |
8192 KB |
Output is correct |
12 |
Correct |
10 ms |
8192 KB |
Output is correct |
13 |
Correct |
8 ms |
8192 KB |
Output is correct |
14 |
Correct |
11 ms |
8192 KB |
Output is correct |
15 |
Correct |
9 ms |
8192 KB |
Output is correct |
16 |
Correct |
12 ms |
8164 KB |
Output is correct |
17 |
Correct |
12 ms |
8192 KB |
Output is correct |
18 |
Correct |
9 ms |
8192 KB |
Output is correct |
19 |
Correct |
13 ms |
8192 KB |
Output is correct |
20 |
Correct |
10 ms |
8192 KB |
Output is correct |
21 |
Correct |
10 ms |
8192 KB |
Output is correct |
22 |
Incorrect |
11 ms |
8192 KB |
Output isn't correct |
23 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
260 ms |
33212 KB |
Output is correct |
2 |
Correct |
251 ms |
33160 KB |
Output is correct |
3 |
Correct |
401 ms |
41052 KB |
Output is correct |
4 |
Correct |
268 ms |
36936 KB |
Output is correct |
5 |
Correct |
306 ms |
36576 KB |
Output is correct |
6 |
Correct |
415 ms |
40316 KB |
Output is correct |
7 |
Correct |
401 ms |
39476 KB |
Output is correct |
8 |
Correct |
374 ms |
40776 KB |
Output is correct |
9 |
Correct |
350 ms |
38072 KB |
Output is correct |
10 |
Correct |
411 ms |
36020 KB |
Output is correct |
11 |
Correct |
251 ms |
31916 KB |
Output is correct |
12 |
Correct |
250 ms |
31688 KB |
Output is correct |
13 |
Correct |
215 ms |
31256 KB |
Output is correct |
14 |
Correct |
244 ms |
30912 KB |
Output is correct |
15 |
Correct |
142 ms |
24872 KB |
Output is correct |
16 |
Correct |
172 ms |
24384 KB |
Output is correct |
17 |
Correct |
12 ms |
8192 KB |
Output is correct |
18 |
Correct |
13 ms |
8192 KB |
Output is correct |
19 |
Correct |
12 ms |
8192 KB |
Output is correct |
20 |
Correct |
12 ms |
8192 KB |
Output is correct |
21 |
Correct |
11 ms |
8164 KB |
Output is correct |
22 |
Correct |
10 ms |
8192 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
13 ms |
8572 KB |
Output is correct |
2 |
Correct |
14 ms |
8576 KB |
Output is correct |
3 |
Correct |
11 ms |
8576 KB |
Output is correct |
4 |
Correct |
13 ms |
8704 KB |
Output is correct |
5 |
Correct |
12 ms |
8576 KB |
Output is correct |
6 |
Correct |
11 ms |
8576 KB |
Output is correct |
7 |
Correct |
13 ms |
8704 KB |
Output is correct |
8 |
Correct |
13 ms |
8576 KB |
Output is correct |
9 |
Correct |
13 ms |
8576 KB |
Output is correct |
10 |
Correct |
11 ms |
8576 KB |
Output is correct |
11 |
Correct |
15 ms |
8576 KB |
Output is correct |
12 |
Correct |
12 ms |
8576 KB |
Output is correct |
13 |
Correct |
12 ms |
8576 KB |
Output is correct |
14 |
Correct |
12 ms |
8576 KB |
Output is correct |
15 |
Correct |
12 ms |
8448 KB |
Output is correct |
16 |
Correct |
11 ms |
8320 KB |
Output is correct |
17 |
Correct |
11 ms |
8448 KB |
Output is correct |
18 |
Correct |
12 ms |
8448 KB |
Output is correct |
19 |
Correct |
11 ms |
8448 KB |
Output is correct |
20 |
Correct |
11 ms |
8448 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
406 ms |
49360 KB |
Output is correct |
2 |
Correct |
406 ms |
49592 KB |
Output is correct |
3 |
Correct |
431 ms |
49520 KB |
Output is correct |
4 |
Correct |
413 ms |
49460 KB |
Output is correct |
5 |
Correct |
413 ms |
49464 KB |
Output is correct |
6 |
Correct |
578 ms |
57784 KB |
Output is correct |
7 |
Correct |
512 ms |
55200 KB |
Output is correct |
8 |
Correct |
479 ms |
53656 KB |
Output is correct |
9 |
Correct |
397 ms |
52152 KB |
Output is correct |
10 |
Correct |
356 ms |
49508 KB |
Output is correct |
11 |
Correct |
449 ms |
49184 KB |
Output is correct |
12 |
Correct |
422 ms |
49116 KB |
Output is correct |
13 |
Correct |
413 ms |
49080 KB |
Output is correct |
14 |
Correct |
393 ms |
47672 KB |
Output is correct |
15 |
Correct |
336 ms |
38292 KB |
Output is correct |
16 |
Correct |
187 ms |
29760 KB |
Output is correct |
17 |
Correct |
282 ms |
41040 KB |
Output is correct |
18 |
Correct |
210 ms |
40752 KB |
Output is correct |
19 |
Correct |
226 ms |
40628 KB |
Output is correct |
20 |
Correct |
253 ms |
40656 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
13 ms |
8572 KB |
Output is correct |
2 |
Correct |
12 ms |
8576 KB |
Output is correct |
3 |
Correct |
13 ms |
8664 KB |
Output is correct |
4 |
Correct |
13 ms |
8448 KB |
Output is correct |
5 |
Correct |
11 ms |
8448 KB |
Output is correct |
6 |
Correct |
12 ms |
8320 KB |
Output is correct |
7 |
Correct |
28 ms |
8320 KB |
Output is correct |
8 |
Correct |
11 ms |
8320 KB |
Output is correct |
9 |
Correct |
11 ms |
8320 KB |
Output is correct |
10 |
Correct |
11 ms |
8320 KB |
Output is correct |
11 |
Correct |
10 ms |
8320 KB |
Output is correct |
12 |
Correct |
11 ms |
8576 KB |
Output is correct |
13 |
Correct |
12 ms |
8576 KB |
Output is correct |
14 |
Correct |
10 ms |
8576 KB |
Output is correct |
15 |
Correct |
11 ms |
8576 KB |
Output is correct |
16 |
Correct |
16 ms |
8448 KB |
Output is correct |
17 |
Correct |
14 ms |
8576 KB |
Output is correct |
18 |
Correct |
12 ms |
8448 KB |
Output is correct |
19 |
Correct |
11 ms |
8448 KB |
Output is correct |
20 |
Correct |
12 ms |
8392 KB |
Output is correct |
21 |
Correct |
10 ms |
8576 KB |
Output is correct |
22 |
Correct |
12 ms |
8576 KB |
Output is correct |
23 |
Correct |
11 ms |
8448 KB |
Output is correct |
24 |
Correct |
11 ms |
8448 KB |
Output is correct |
25 |
Correct |
10 ms |
8192 KB |
Output is correct |
26 |
Correct |
11 ms |
8192 KB |
Output is correct |
27 |
Correct |
10 ms |
8192 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
452 ms |
49452 KB |
Output is correct |
2 |
Correct |
474 ms |
49468 KB |
Output is correct |
3 |
Correct |
465 ms |
48056 KB |
Output is correct |
4 |
Correct |
462 ms |
35616 KB |
Output is correct |
5 |
Correct |
299 ms |
28856 KB |
Output is correct |
6 |
Correct |
318 ms |
25960 KB |
Output is correct |
7 |
Correct |
260 ms |
25420 KB |
Output is correct |
8 |
Correct |
264 ms |
22064 KB |
Output is correct |
9 |
Correct |
215 ms |
21584 KB |
Output is correct |
10 |
Correct |
213 ms |
20304 KB |
Output is correct |
11 |
Correct |
209 ms |
19340 KB |
Output is correct |
12 |
Correct |
199 ms |
18524 KB |
Output is correct |
13 |
Correct |
215 ms |
18680 KB |
Output is correct |
14 |
Correct |
243 ms |
22056 KB |
Output is correct |
15 |
Correct |
543 ms |
55108 KB |
Output is correct |
16 |
Correct |
417 ms |
53020 KB |
Output is correct |
17 |
Correct |
439 ms |
46136 KB |
Output is correct |
18 |
Correct |
520 ms |
43792 KB |
Output is correct |
19 |
Correct |
408 ms |
35604 KB |
Output is correct |
20 |
Correct |
426 ms |
35464 KB |
Output is correct |
21 |
Correct |
391 ms |
35560 KB |
Output is correct |
22 |
Correct |
307 ms |
33744 KB |
Output is correct |
23 |
Correct |
234 ms |
28224 KB |
Output is correct |
24 |
Correct |
299 ms |
41092 KB |
Output is correct |
25 |
Correct |
324 ms |
40992 KB |
Output is correct |
26 |
Correct |
303 ms |
38848 KB |
Output is correct |
27 |
Correct |
312 ms |
38580 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
10 ms |
8192 KB |
Output is correct |
2 |
Correct |
10 ms |
8192 KB |
Output is correct |
3 |
Correct |
9 ms |
8192 KB |
Output is correct |
4 |
Correct |
10 ms |
8192 KB |
Output is correct |
5 |
Correct |
11 ms |
8192 KB |
Output is correct |
6 |
Correct |
10 ms |
8192 KB |
Output is correct |
7 |
Correct |
10 ms |
8192 KB |
Output is correct |
8 |
Correct |
11 ms |
8192 KB |
Output is correct |
9 |
Correct |
9 ms |
8192 KB |
Output is correct |
10 |
Correct |
9 ms |
8192 KB |
Output is correct |
11 |
Correct |
10 ms |
8192 KB |
Output is correct |
12 |
Correct |
10 ms |
8192 KB |
Output is correct |
13 |
Correct |
8 ms |
8192 KB |
Output is correct |
14 |
Correct |
11 ms |
8192 KB |
Output is correct |
15 |
Correct |
9 ms |
8192 KB |
Output is correct |
16 |
Correct |
12 ms |
8164 KB |
Output is correct |
17 |
Correct |
12 ms |
8192 KB |
Output is correct |
18 |
Correct |
9 ms |
8192 KB |
Output is correct |
19 |
Correct |
13 ms |
8192 KB |
Output is correct |
20 |
Correct |
10 ms |
8192 KB |
Output is correct |
21 |
Correct |
10 ms |
8192 KB |
Output is correct |
22 |
Incorrect |
11 ms |
8192 KB |
Output isn't correct |
23 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
10 ms |
8192 KB |
Output is correct |
2 |
Correct |
10 ms |
8192 KB |
Output is correct |
3 |
Correct |
9 ms |
8192 KB |
Output is correct |
4 |
Correct |
10 ms |
8192 KB |
Output is correct |
5 |
Correct |
11 ms |
8192 KB |
Output is correct |
6 |
Correct |
10 ms |
8192 KB |
Output is correct |
7 |
Correct |
10 ms |
8192 KB |
Output is correct |
8 |
Correct |
11 ms |
8192 KB |
Output is correct |
9 |
Correct |
9 ms |
8192 KB |
Output is correct |
10 |
Correct |
9 ms |
8192 KB |
Output is correct |
11 |
Correct |
10 ms |
8192 KB |
Output is correct |
12 |
Correct |
10 ms |
8192 KB |
Output is correct |
13 |
Correct |
8 ms |
8192 KB |
Output is correct |
14 |
Correct |
11 ms |
8192 KB |
Output is correct |
15 |
Correct |
9 ms |
8192 KB |
Output is correct |
16 |
Correct |
12 ms |
8164 KB |
Output is correct |
17 |
Correct |
12 ms |
8192 KB |
Output is correct |
18 |
Correct |
9 ms |
8192 KB |
Output is correct |
19 |
Correct |
13 ms |
8192 KB |
Output is correct |
20 |
Correct |
10 ms |
8192 KB |
Output is correct |
21 |
Correct |
10 ms |
8192 KB |
Output is correct |
22 |
Incorrect |
11 ms |
8192 KB |
Output isn't correct |
23 |
Halted |
0 ms |
0 KB |
- |