#include<bits/stdc++.h>
#define pb emplace_back
using namespace std;
using ll = long long;
const int maxn = 300010;
int n, m;
vector<int> edge[maxn];
int low[maxn], st[maxn], stl, dep[maxn];
int cnt_b;
ll gsz;
vector<int> c[maxn];
bool is_ap[maxn];
ll res;
int h;
#define c2(i) ((ll)(i) * ((ll)(i)-1) / 2)
#define p3(i) ((ll)(i) * ((ll)(i)-1) * ((ll)(i)-2))
vector<int> tree_edge[maxn];
int sz[maxn];
void dfs2(int now, int last = 0){
sz[now] = c[now].size() + (now <= n);
for (int u : tree_edge[now]) if(u != last) {
dfs2(u, now);
sz[now] += sz[u] - 1;
}
//
// if (now > n){
// ll apc = 0;
// //cout << "now ";
// for (int u : c[now])
// apc += is_ap[u];//, cout << u << ' ';
// if (!apc){
// res += p3(c[now].size());
// return ;
// }
// ll o = res;
// auto add = [&](ll a_with_ap, ll b_with_ap, ll all) {
// res += 2 * (b_with_ap) * (a_with_ap - 1 - apc) * (a_with_ap - apc);
// };
// for (int u : tree_edge[now]) if(u != last)
// add(c[now].size(), sz[u], gsz);
// if (last)
// add(c[now].size(), gsz - sz[now]+1, gsz);
// res += ((ll)c[now].size()-apc) * ((ll)c[now].size()-apc-1) * ((ll)c[now].size()-2);
// //cout << " add " << res-o << '\n';
// }
if (now > n){
ll apc = 0, cur = c[now].size();
//cout << "now ";
for (int u : c[now])
apc += is_ap[u];//, cout << u << ' ';
res += (cur-apc) * (gsz - cur + apc) * (cur-apc-1) * 2;
res += (cur-apc) * (cur-apc-1) * (cur-2);
for (int u : tree_edge[now]) if(u != last)
res += sz[u] * (gsz - sz[u] - cur + 1) * (cur-apc);
if (last)
res += (gsz - sz[now]+1) * (sz[now] - c[now].size()+apc-1) * (cur-apc);
}
else {
auto add = [&](ll a, ll all){
res += (a-1) * (all-a);
};
for (int u : tree_edge[now]) if(u != last)
add(sz[u], gsz);
if (last)
add(gsz - sz[now]+1, gsz);
assert(last);
}
}
void cal(){
for (int i = h;i < cnt_b;++i){
for (int u : c[i]) if (is_ap[u]) {
tree_edge[u].pb(i);
tree_edge[i].pb(u);
}
}
dfs2(h);
gsz = 0, h = cnt_b;
}
void dfs(int now, int last = 0){
static int d;
++gsz;
low[now] = dep[now] = ++d;
st[stl++] = now;
int cnt_c = 0;
for (int u : edge[now]) if (u != last) {
if (!low[u]){
dfs(u, now);
++cnt_c;
low[now] = min(low[now], low[u]);
if (low[u] >= dep[now]){
do {
c[cnt_b].pb( st[--stl] );
} while (st[stl] != u);
c[cnt_b++].pb(now);
is_ap[now] = true;
}
}
else
low[now] = min(low[now], dep[u]);
}
if (last == 0 && cnt_c < 2)
is_ap[now] = false;
--d;
if (last == 0)
cal();
}
signed main(){
ios_base::sync_with_stdio(0), cin.tie(0);
cin >> n >> m;
for ( int a, b, i = 0 ; i < m ; ++i) {
cin >> a >> b;
edge[a].pb(b);
edge[b].pb(a);
}
h = cnt_b = n+1;
for (int i = 1;i <= n;++i) if (!low[i])
dfs(i);
cout << res << '\n';
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
19 ms |
21496 KB |
Output is correct |
2 |
Correct |
19 ms |
21496 KB |
Output is correct |
3 |
Correct |
18 ms |
21496 KB |
Output is correct |
4 |
Correct |
19 ms |
21496 KB |
Output is correct |
5 |
Correct |
18 ms |
21496 KB |
Output is correct |
6 |
Correct |
18 ms |
21496 KB |
Output is correct |
7 |
Incorrect |
18 ms |
21496 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
19 ms |
21496 KB |
Output is correct |
2 |
Correct |
19 ms |
21496 KB |
Output is correct |
3 |
Correct |
18 ms |
21496 KB |
Output is correct |
4 |
Correct |
19 ms |
21496 KB |
Output is correct |
5 |
Correct |
18 ms |
21496 KB |
Output is correct |
6 |
Correct |
18 ms |
21496 KB |
Output is correct |
7 |
Incorrect |
18 ms |
21496 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
96 ms |
34292 KB |
Output is correct |
2 |
Correct |
102 ms |
34344 KB |
Output is correct |
3 |
Correct |
119 ms |
40564 KB |
Output is correct |
4 |
Correct |
103 ms |
35172 KB |
Output is correct |
5 |
Correct |
108 ms |
35828 KB |
Output is correct |
6 |
Correct |
129 ms |
42100 KB |
Output is correct |
7 |
Correct |
135 ms |
36088 KB |
Output is correct |
8 |
Correct |
131 ms |
38904 KB |
Output is correct |
9 |
Correct |
136 ms |
33912 KB |
Output is correct |
10 |
Correct |
119 ms |
34296 KB |
Output is correct |
11 |
Correct |
110 ms |
29820 KB |
Output is correct |
12 |
Correct |
100 ms |
29688 KB |
Output is correct |
13 |
Correct |
89 ms |
29044 KB |
Output is correct |
14 |
Correct |
89 ms |
29048 KB |
Output is correct |
15 |
Correct |
68 ms |
27768 KB |
Output is correct |
16 |
Correct |
76 ms |
27828 KB |
Output is correct |
17 |
Correct |
21 ms |
22776 KB |
Output is correct |
18 |
Correct |
22 ms |
22776 KB |
Output is correct |
19 |
Correct |
21 ms |
22824 KB |
Output is correct |
20 |
Correct |
21 ms |
22776 KB |
Output is correct |
21 |
Correct |
21 ms |
22776 KB |
Output is correct |
22 |
Correct |
21 ms |
22776 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
19 ms |
21592 KB |
Output is correct |
2 |
Correct |
21 ms |
21624 KB |
Output is correct |
3 |
Correct |
20 ms |
21624 KB |
Output is correct |
4 |
Correct |
20 ms |
21752 KB |
Output is correct |
5 |
Correct |
20 ms |
21752 KB |
Output is correct |
6 |
Correct |
19 ms |
21752 KB |
Output is correct |
7 |
Correct |
20 ms |
21752 KB |
Output is correct |
8 |
Correct |
20 ms |
21624 KB |
Output is correct |
9 |
Correct |
19 ms |
21756 KB |
Output is correct |
10 |
Correct |
19 ms |
21628 KB |
Output is correct |
11 |
Correct |
20 ms |
21624 KB |
Output is correct |
12 |
Correct |
20 ms |
21624 KB |
Output is correct |
13 |
Correct |
19 ms |
21756 KB |
Output is correct |
14 |
Correct |
19 ms |
21624 KB |
Output is correct |
15 |
Correct |
19 ms |
21624 KB |
Output is correct |
16 |
Correct |
19 ms |
21496 KB |
Output is correct |
17 |
Correct |
18 ms |
21624 KB |
Output is correct |
18 |
Correct |
19 ms |
21624 KB |
Output is correct |
19 |
Correct |
19 ms |
21624 KB |
Output is correct |
20 |
Correct |
19 ms |
21624 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
125 ms |
34424 KB |
Output is correct |
2 |
Correct |
135 ms |
34296 KB |
Output is correct |
3 |
Correct |
133 ms |
34424 KB |
Output is correct |
4 |
Correct |
127 ms |
34296 KB |
Output is correct |
5 |
Correct |
123 ms |
34424 KB |
Output is correct |
6 |
Correct |
154 ms |
54648 KB |
Output is correct |
7 |
Correct |
145 ms |
41848 KB |
Output is correct |
8 |
Correct |
139 ms |
39928 KB |
Output is correct |
9 |
Correct |
139 ms |
38136 KB |
Output is correct |
10 |
Correct |
134 ms |
34296 KB |
Output is correct |
11 |
Correct |
127 ms |
34424 KB |
Output is correct |
12 |
Correct |
135 ms |
34296 KB |
Output is correct |
13 |
Correct |
131 ms |
34296 KB |
Output is correct |
14 |
Correct |
130 ms |
33528 KB |
Output is correct |
15 |
Correct |
114 ms |
32504 KB |
Output is correct |
16 |
Correct |
74 ms |
28920 KB |
Output is correct |
17 |
Correct |
81 ms |
32860 KB |
Output is correct |
18 |
Correct |
77 ms |
32880 KB |
Output is correct |
19 |
Correct |
83 ms |
33004 KB |
Output is correct |
20 |
Correct |
81 ms |
32888 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
20 ms |
21624 KB |
Output is correct |
2 |
Correct |
21 ms |
21624 KB |
Output is correct |
3 |
Incorrect |
22 ms |
21624 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
128 ms |
34296 KB |
Output is correct |
2 |
Correct |
135 ms |
34684 KB |
Output is correct |
3 |
Incorrect |
141 ms |
33272 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
19 ms |
21496 KB |
Output is correct |
2 |
Correct |
19 ms |
21496 KB |
Output is correct |
3 |
Correct |
18 ms |
21496 KB |
Output is correct |
4 |
Correct |
19 ms |
21496 KB |
Output is correct |
5 |
Correct |
18 ms |
21496 KB |
Output is correct |
6 |
Correct |
18 ms |
21496 KB |
Output is correct |
7 |
Incorrect |
18 ms |
21496 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
19 ms |
21496 KB |
Output is correct |
2 |
Correct |
19 ms |
21496 KB |
Output is correct |
3 |
Correct |
18 ms |
21496 KB |
Output is correct |
4 |
Correct |
19 ms |
21496 KB |
Output is correct |
5 |
Correct |
18 ms |
21496 KB |
Output is correct |
6 |
Correct |
18 ms |
21496 KB |
Output is correct |
7 |
Incorrect |
18 ms |
21496 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |