#include <bits/stdc++.h>
#define FOR(i, x, y) for (int i = x; i < y; i++)
typedef long long ll;
using namespace std;
ll n, m, N, ans, sz[200001];
vector<int> graph[100001], bcc_graph[200001], stck;
int low[100001], tin[100001], timer = 1, bccs = 1;
void dfs(int node, int parent = 0) {
low[node] = tin[node] = timer++;
stck.push_back(node);
N++;
for (int i : graph[node])
if (i != parent) {
if (tin[i]) low[node] = min(low[node], tin[i]);
else {
dfs(i, node);
low[node] = min(low[node], low[i]);
if (low[i] >= tin[node]) {
bcc_graph[node].push_back(n + bccs);
while (1) {
if(stck.empty())
break;
sz[n + bccs]++;
//bcc_graph[n + bccs].push_back(stck.back());
//cout<<n+bccs<<' '<<stck.back()<<'\n';
int res = stck.back();
stck.pop_back();
if(res == i)
break;
}
//cout<<node<<' '<<n+bccs<<' '<<sz[n+bccs]<<'\n';
bccs++;
}
}
}
}
void dfs2(int node) {
sz[node] += (node <= n);
for (int i : bcc_graph[node]) {
//cout<<node<<' '<<i<<'\n';
dfs2(i);
sz[node] += sz[i];
//if (node > n)
{
ans -= (N - sz[i]) * sz[i] * (sz[i] - 1);
//cout<<node<<' '<<(N - sz[i])<<' '<<i<<' '<<sz[i]<<'\n';
}
}
//if (node > n)
{
ans -= sz[node] * (N - sz[node]) * (N - sz[node] - 1);
//cout<<node<<' '<<sz[node]<<' '<<N-sz[node]<<'\n';
}
}
int main() {
ios_base::sync_with_stdio(0);
cin.tie(0);
cin >> n >> m;
while (m--) {
int u, v;
cin >> u >> v;
graph[u].push_back(v);
graph[v].push_back(u);
}
FOR(i, 1, n + 1) if (!tin[i]) {
N = 0;
dfs(i);
ans += N * (N - 1) * (N - 2);
dfs2(i);
}
cout << ans;
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
7380 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
7380 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
38 ms |
22340 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
4 ms |
7380 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
50 ms |
15000 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
4 ms |
7388 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
59 ms |
14940 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
7380 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
7380 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |