#include <bits/stdc++.h>
using namespace std;
typedef pair<long long,long long> PLL;
typedef long long LL;
#define ln '\n'
#define faster {ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);}
#define all(v) v.begin(),v.end()
int mod = 998244353;
const int N = 4e5 + 10;
const int inf = 1e9;
bitset <N> art, good;
vector <int> g[N], tree[N], st, comp[N];
int n, m, ptr, cur, in[N], low[N], id[N];
void dfs (int u, int from = -1) {
in[u] = low[u] = ++ptr;
st.emplace_back(u);
for (int v : g[u]) if (v ^ from) {
if (!in[v]) {
dfs(v, u);
low[u] = min(low[u], low[v]);
if (low[v] >= in[u]) {
art[u] = in[u] > 1 or in[v] > 2;
comp[++cur].emplace_back(u);
while (comp[cur].back() ^ v) {
comp[cur].emplace_back(st.back());
st.pop_back();
}
}
} else {
low[u] = min(low[u], in[v]);
}
}
}
void buildTree(int n) {
ptr = 0;
for (int i = 1; i <= n; ++i) {
if (art[i]) id[i] = ++ptr;
}
for (int i = 1; i <= cur; ++i) {
int x = ++ptr;
for (int u : comp[i]) {
if (art[u]) {
tree[x].emplace_back(id[u]);
tree[id[u]].emplace_back(x);
} else {
id[u] = x;
}
}
}
}
void solve(int test){
int n, m, q; cin>>n>>m;
for(int i = 0, u, v; i < m; i++){
cin>>u>>v;
g[u].push_back(v); g[v].push_back(u);
}
dfs(1);
auto nC2 = [&](LL n){
return n * (n - 1) / 2;
};
auto nC3 = [&](LL n){
return n * (n - 1) * (n - 2) / 6;
};
LL ans = nC3(n);
for(int i = 1; i <= cur; i++){
int sz = comp[i].size();
int artP = 0;
for(int j = 0; j < sz; j++)
artP += art[comp[i][j]];
LL tmp = nC3(sz) * 2 + nC2(sz - 1) * (n - sz);
ans += tmp;
}
cout<<ans * 2<<'\n';
}
signed main(){
faster
int t = 1;
// cin>>t;
for(int i = 1; i <= t; i++){
solve(i);
}
return 0;
}
Compilation message
count_triplets.cpp: In function 'void solve(int)':
count_triplets.cpp:61:15: warning: unused variable 'q' [-Wunused-variable]
61 | int n, m, q; cin>>n>>m;
| ^
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
12 ms |
28508 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
12 ms |
28508 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
44 ms |
44232 KB |
Output is correct |
2 |
Correct |
43 ms |
44232 KB |
Output is correct |
3 |
Incorrect |
38 ms |
39004 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
12 ms |
28652 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
42 ms |
36880 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
11 ms |
28508 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
44 ms |
36948 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
12 ms |
28508 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
12 ms |
28508 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |