#include <bits/stdc++.h>
using namespace std;
const int MAXN = 2e5 + 25;
vector <int> adj[MAXN];
int n, m;
int dep[MAXN], low[MAXN];
vector <int> adj2[MAXN];
int cnt, sze2;
long long ans;
vector <int> cur;
void dfs (int pos, int par, int tt) {
dep[pos] = low[pos] = tt; cur.push_back(pos);
sze2++;
for (auto j : adj[pos]) {
if (j == par) continue;
if (dep[j]) {
low[pos] = min(low[pos], dep[j]);
} else {
dfs(j, pos, tt + 1);
low[pos] = min(low[pos], low[j]);
if (low[j] >= dep[pos]) {
++cnt;
adj2[pos].push_back(n + cnt);
while (adj2[n + cnt].empty() || adj2[n + cnt].back() != j) {
adj2[n + cnt].push_back(cur.back());
cur.pop_back();
}
}
}
}
}
int sze[MAXN];
void dfs2 (int pos, int par) {
if (pos <= n) sze[pos] = 1;
long long l = adj2[pos].size();
for (auto j : adj2[pos]) {
dfs2(j, pos);
sze[pos] += sze[j];
if (pos > n) {
ans -= 1ll * sze[j] * (sze[j] - 1) * l;
}
}
if (pos > n) {
ans -= 1ll * (sze2 - sze[pos]) * (sze2 - sze[pos] - 1) * l;
}
}
int main () {
ios::sync_with_stdio(0); cin.tie(0);
cin >> n >> m;
for (int i = 1; i <= m; i++) {
int a, b;
cin >> a >> b;
adj[a].push_back(b);
adj[b].push_back(a);
}
memset(dep, -1, sizeof(dep));
for (int i = 1; i <= n; i++) {
if (-1 == dep[i]) {
sze2 = 0; cur.clear();
dfs(i, -1, 0);
ans += sze2 * (sze2 - 1) * (sze2 - 2);
dfs2(i, -1);
}
}
cout << ans << '\n';
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
11864 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
11864 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
35 ms |
17028 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
11868 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
46 ms |
17508 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
11864 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
38 ms |
17272 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
11864 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
3 ms |
11864 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |