#include<bits/stdc++.h>
using namespace std;
#define ll long long
vector<vector<int>> graph;
vector<vector<int>> cgraph;
vector<int> comp;
vector<int> art;
vector<int> low;
vector<int> num;
vector<int> vis;
stack<int> s;
int c = 0;
int d = 0;
int root = 0;
int sub = 0;
vector<ll> compsize;
ll sol = 0;
int n, m;
void dfs(int i, int p)
{
num[i] = low[i] = ++c;
s.push(i);
for (int ele:graph[i])
{
if (ele == p) continue;
if (!num[ele])
{
if (i == root) sub++;
dfs(ele, i);
if (low[ele]>=num[i]) art[i] = 1;
if (low[ele]==num[i])
{
while(s.top() != i)
{
comp[s.top()] = d;
compsize[d]++;
s.pop();
}
comp[i] = d;
compsize[d]++;
s.pop();
d++;
}
}
low[i] = min(low[i], low[ele]);
}
if (num[i]==low[i] && comp[i]==-1)
{
art[i] = 1;
while (s.top() != i)
{
comp[s.top()] = d;
compsize[d]++;
s.pop();
}
comp[i] = d;
compsize[d]++;
s.pop();
d++;
}
}
int dfs2(int i)
{
vis[i] = 1;
ll ss = 0;
vector<int> cs;
vector<int> v;
for (int ele:cgraph[i])
{
if (!vis[ele])
{
if (ele < n) cs.push_back(compsize[ele]-1);
int h = dfs2(ele);
if (ele < n) h--;
v.push_back(h);
ss += v.back();
}
}
if (i >= n)
{
for (ll ele:cs)
{
if (ele) sol += (ele-1)*(ele-2);
}
for (ll ele:v)
{
sol += ele*(sub-ele-1);
}
}
else
{
sol += (compsize[i]-1)*(compsize[i]-2)*compsize[i];
for (ll ele:v)
{
sol += ele*(sub-ele-1)*compsize[i];
}
}
return ss+1;
}
int main()
{
//freopen("input.txt", "r", stdin);
//freopen("output.txt", "w", stdout);
cin >> n >> m;
graph.assign(n, vector<int>());
cgraph.assign(2*n, vector<int>());
compsize.assign(n, 0);
low.assign(n, 0);
num.assign(n, 0);
comp.assign(n, -1);
art.assign(n, 0);
vis.assign(2*n, 0);
for (int i =0; i < m; i++)
{
int a, b;
cin >> a >> b;
a--; b--;
graph[a].push_back(b);
graph[b].push_back(a);
}
vector<int> subtree(n, 0);
for (int i = 0; i < n; i++)
{
if (!num[i])
{
root = i;
sub = 0;
c = 0;
dfs(i, -1);
subtree[i] = c;
if (sub==1) art[i] = 0;
}
}
d = n;
for (int i = 0; i <n; i++)
{
if (art[i])
{
for (int ele:graph[i])
{
cgraph[d].push_back(comp[ele]);
cgraph[ele].push_back(d);
}
comp[i] = d;
d++;
}
}
for (int i = 0; i < n; i++)
{
if (!vis[comp[i]])
{
sub = subtree[i];
dfs2(comp[i]);
}
}
cout << sol << "\n";
return 0;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
1 ms |
348 KB |
Output is correct |
7 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
1 ms |
348 KB |
Output is correct |
7 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
75 ms |
22352 KB |
Output is correct |
2 |
Correct |
73 ms |
23376 KB |
Output is correct |
3 |
Incorrect |
100 ms |
22548 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
600 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
179 ms |
29772 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
1 ms |
600 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
147 ms |
29748 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
1 ms |
348 KB |
Output is correct |
7 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
1 ms |
348 KB |
Output is correct |
6 |
Correct |
1 ms |
348 KB |
Output is correct |
7 |
Incorrect |
0 ms |
348 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |