#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MAXN = 1e5;
vector<int> edges[MAXN];
vector<int> bcc_graph[2*MAXN];
int n, m;
ll csize;
int num_bcc = 0;
int depth[MAXN];
int lp[MAXN];
bool vis[MAXN];
vector<int> stck;
ll sz[MAXN];
ll ans = 0;
void make_bcc(int cur, int p = -1) {
lp[cur] = depth[cur];
vis[cur] = 1;
stck.push_back(cur);
csize++;
for (int next: edges[cur]) {
if (next == p) continue;
if (vis[next]) {
lp[cur] = min(lp[cur], depth[next]);
continue;
}
depth[next] = 1+depth[cur];
make_bcc(next, cur);
lp[cur] = min(lp[cur], lp[next]);
if (lp[next] >= depth[cur]) {
int cur_bcc = n+(num_bcc++);
bcc_graph[cur].push_back(cur_bcc);
bcc_graph[cur_bcc].push_back(cur);
while (stck.back() != cur) {
int b = stck.back();
stck.pop_back();
bcc_graph[b].push_back(cur_bcc);
bcc_graph[cur_bcc].push_back(b);
}
}
}
}
void make_ans(int cur, int p = -1) {
if (cur < n) sz[cur]++;
for (int next: bcc_graph[cur]) {
if (next == p) continue;
make_ans(next, cur);
sz[cur] += sz[next];
if (cur >= n) ans -= sz[next]*(sz[next]-1)*(bcc_graph[cur].size()-1); // can't include this articulation point as a midpoint
}
ll out_sz = n-sz[cur];
if (cur >= n) ans -= out_sz*(out_sz-1)*(bcc_graph[cur].size()-1);
}
int main() {
ios_base::sync_with_stdio(false); cin.tie(NULL);
cin >> n >> m;
for (int i = 0; i < m; i++) {
int x, y; cin >> x >> y; x--; y--;
edges[x].push_back(y);
edges[y].push_back(x);
}
for (int i = 0; i < n; i++) {
if (vis[i]) continue;
csize = 0;
make_bcc(i);
ans += csize*(csize-1)*(csize-2);
make_ans(i);
}
cout << ans << "\n";
}
# |
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 |
4 ms |
7380 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
86 ms |
55876 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
4 ms |
7508 KB |
Output is correct |
2 |
Correct |
4 ms |
7508 KB |
Output is correct |
3 |
Correct |
5 ms |
7516 KB |
Output is correct |
4 |
Correct |
4 ms |
7520 KB |
Output is correct |
5 |
Correct |
4 ms |
7508 KB |
Output is correct |
6 |
Correct |
5 ms |
7508 KB |
Output is correct |
7 |
Correct |
4 ms |
7588 KB |
Output is correct |
8 |
Correct |
4 ms |
7508 KB |
Output is correct |
9 |
Correct |
5 ms |
7508 KB |
Output is correct |
10 |
Incorrect |
4 ms |
7508 KB |
Output isn't correct |
11 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
206 ms |
38812 KB |
Execution killed with signal 6 |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
5 ms |
7508 KB |
Output is correct |
2 |
Correct |
4 ms |
7636 KB |
Output is correct |
3 |
Incorrect |
4 ms |
7392 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Runtime error |
91 ms |
38812 KB |
Execution killed with signal 6 |
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 |
4 ms |
7380 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |