#include <bits/stdc++.h>
using namespace std;
#define int long long
mt19937_64 RNG(chrono::steady_clock::now().time_since_epoch().count());
/*
- Make a bridge tree of the graph
- Store all the sizes of the nodes in bridge tree
- Case 1:
All 3 nodes in the same node (all s, c, f)
(siz) * (siz - 1) * (siz - 2)
- Case 2: 2 nodes in the same node. 1 node away (s, c) or (c, f)
s / f cannot be the node that joins the bridge node and the away node
=> -1 candidate for f, same candidates for c
=> [[(component_siz - siz) * (siz - 1) * (siz - 1)]] * 2 (for the 2 options)
- Case 3: 1 node here, 2 nodes in different subtrees (c)
=> if bridge is from same node, only that node can be c
=> else, siz options
*/
const int INF = 1e18;
const int N = 1e5 + 5;
bool vis[N]; // visited track
vector<int> g[N]; // graph
vector<array<int, 2> > bcc[N]; // bridge tree graph (to, connector)
int low[N], disc[N], tim = 1;
set<pair<int, int> > bridges;
int siz[N], component[N]; // size of bridge tree node i, component of node i of original graph
int subtree[N];
int tot_siz[N]; // total size of the bridge tree component
int ans = 0;
void dfs(int node, int par)
{
low[node] = tim;
disc[node] = tim++;
vis[node] = true;
for(int to: g[node])
{
if(to == par) continue;
if(vis[to])
{
low[node] = min(low[node], disc[to]);
}
else
{
dfs(to, node);
low[node] = min(low[node], low[to]);
if(low[to] > disc[node])
{
bridges.insert({node, to});
bridges.insert({to, node});
}
}
}
}
void add_component(int node, int par, int comp)
{
siz[comp] += 1;
component[node] = comp;
vis[node] = true;
for(int to: g[node])
{
if(vis[to]) continue;
if(bridges.count({node, to}))
{
continue;
}
add_component(to, node, comp);
}
}
int FindSiz(int node)
{
subtree[node] = siz[node];
int ans = siz[node];
vis[node] = true;
for(auto [to, temp]: bcc[node])
{
if(vis[to]) continue;
ans += FindSiz(to);
subtree[node] += subtree[to];
}
return ans;
}
void UpdateSiz(int node, int val)
{
tot_siz[node] = val;
for(auto [to, temp]: bcc[node])
{
if(tot_siz[to] != val)
{
UpdateSiz(to, val);
}
}
}
void Solve()
{
int n, m;
cin >> n >> m;
for(int i = 1; i <= m; i++)
{
int u, v;
cin >> u >> v;
g[u].push_back(v);
g[v].push_back(u);
}
for(int i = 1; i <= n; i++)
{
if(!vis[i])
{
dfs(i, -1);
}
}
for(int i = 1; i <= n; i++)
{
vis[i] = false;
}
int cnt = 0;
for(int i = 1; i <= n; i++)
{
if(!vis[i])
{
cnt += 1;
add_component(i, -1, cnt);
}
}
for(auto [u, v]: bridges)
{
bcc[component[u]].push_back({component[v], u});
}
// implementing case 1:
for(int i = 1; i <= cnt; i++)
{
ans += siz[i] * (siz[i] - 1) * (siz[i] - 2);
}
// implementation ends
for(int i = 1; i <= cnt; i++)
{
vis[i] = false;
}
for(int i = 1; i <= cnt; i++)
{
if(!vis[i])
{
int temp = FindSiz(i);
UpdateSiz(i, temp);
}
}
// implementing case 2:
for(int i = 1; i <= cnt; i++)
{
ans += (tot_siz[i] - siz[i]) * (siz[i] - 1) * (siz[i] - 1) * 2LL;
}
// implementation ends
// implementing case 3:
// cout << "subtree\n";
// for(int i = 1; i <= n; i++)
// {
// cout << subtree[i] << " ";
// }
// cout << "\n";
for(int i = 1; i <= cnt; i++)
{
// cout << "tot_siz[i] = " << tot_siz[i] << ", siz[i] = " << siz[i] << "\n";
// cout << "subtree[i] = " << subtree[i] << endl;
map<int, int> mp;
for(auto [to, connector]: bcc[i])
{
// cout << "to = " << to << ", connector = " << connector << "\n";
mp[connector] += subtree[to];
if(subtree[to] > subtree[i])
{
mp[connector] -= subtree[to];
mp[connector] += (tot_siz[i] - subtree[i]);
}
}
// for(auto i: mp)
// {
// cout << "connector: " << i.first << ", connector size = " << i.second << "\n";
// }
for(auto [to, connector]: bcc[i])
{
int going = subtree[to];
if(subtree[to] > subtree[i])
{
going = tot_siz[i] - subtree[i];
}
int excluding_this = tot_siz[i] - siz[i] - mp[connector];
// cout << "excluding_this = " << excluding_this << "\n";
int cur_ans = 0;
// cout << "siz[to] = " << going << ", left = " << mp[connector] - subtree[to] << "\n";
// only one node usable
cur_ans += (going * (mp[connector] - going));
// all usable
cur_ans += (going * siz[i] * excluding_this);
ans += cur_ans;
// cout << "ans = " << ans << "\n";
}
}
cout << ans << "\n";
}
int32_t main()
{
auto begin = std::chrono::high_resolution_clock::now();
ios_base::sync_with_stdio(0);
cin.tie(0);
int t = 1;
// cin >> t;
for(int i = 1; i <= t; i++)
{
//cout << "Case #" << i << ": ";
Solve();
}
auto end = std::chrono::high_resolution_clock::now();
auto elapsed = std::chrono::duration_cast<std::chrono::nanoseconds>(end - begin);
//cerr << "Time measured: " << elapsed.count() * 1e-9 << " seconds.\n";
return 0;
}
Compilation message
count_triplets.cpp: In function 'long long int FindSiz(long long int)':
count_triplets.cpp:87:11: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
87 | for(auto [to, temp]: bcc[node])
| ^
count_triplets.cpp: In function 'void UpdateSiz(long long int, long long int)':
count_triplets.cpp:99:11: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
99 | for(auto [to, temp]: bcc[node])
| ^
count_triplets.cpp: In function 'void Solve()':
count_triplets.cpp:139:11: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
139 | for(auto [u, v]: bridges)
| ^
count_triplets.cpp:183:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
183 | for(auto [to, connector]: bcc[i])
| ^
count_triplets.cpp:197:12: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
197 | for(auto [to, connector]: bcc[i])
| ^
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Correct |
3 ms |
4948 KB |
Output is correct |
3 |
Correct |
3 ms |
4948 KB |
Output is correct |
4 |
Correct |
3 ms |
4948 KB |
Output is correct |
5 |
Correct |
3 ms |
5004 KB |
Output is correct |
6 |
Correct |
3 ms |
4948 KB |
Output is correct |
7 |
Correct |
3 ms |
4948 KB |
Output is correct |
8 |
Incorrect |
3 ms |
4948 KB |
Output isn't correct |
9 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Correct |
3 ms |
4948 KB |
Output is correct |
3 |
Correct |
3 ms |
4948 KB |
Output is correct |
4 |
Correct |
3 ms |
4948 KB |
Output is correct |
5 |
Correct |
3 ms |
5004 KB |
Output is correct |
6 |
Correct |
3 ms |
4948 KB |
Output is correct |
7 |
Correct |
3 ms |
4948 KB |
Output is correct |
8 |
Incorrect |
3 ms |
4948 KB |
Output isn't correct |
9 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
73 ms |
21460 KB |
Output is correct |
2 |
Correct |
77 ms |
21452 KB |
Output is correct |
3 |
Correct |
153 ms |
25732 KB |
Output is correct |
4 |
Correct |
118 ms |
24908 KB |
Output is correct |
5 |
Correct |
132 ms |
22012 KB |
Output is correct |
6 |
Correct |
160 ms |
26232 KB |
Output is correct |
7 |
Correct |
182 ms |
25704 KB |
Output is correct |
8 |
Correct |
172 ms |
26652 KB |
Output is correct |
9 |
Correct |
167 ms |
24624 KB |
Output is correct |
10 |
Correct |
153 ms |
23676 KB |
Output is correct |
11 |
Correct |
128 ms |
19988 KB |
Output is correct |
12 |
Correct |
108 ms |
19972 KB |
Output is correct |
13 |
Correct |
103 ms |
19896 KB |
Output is correct |
14 |
Correct |
107 ms |
19556 KB |
Output is correct |
15 |
Correct |
87 ms |
18948 KB |
Output is correct |
16 |
Correct |
83 ms |
18356 KB |
Output is correct |
17 |
Correct |
8 ms |
9780 KB |
Output is correct |
18 |
Correct |
8 ms |
9776 KB |
Output is correct |
19 |
Correct |
8 ms |
9812 KB |
Output is correct |
20 |
Correct |
7 ms |
9812 KB |
Output is correct |
21 |
Correct |
7 ms |
9776 KB |
Output is correct |
22 |
Correct |
7 ms |
9812 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
5204 KB |
Output is correct |
2 |
Correct |
4 ms |
5204 KB |
Output is correct |
3 |
Correct |
4 ms |
5204 KB |
Output is correct |
4 |
Correct |
4 ms |
5332 KB |
Output is correct |
5 |
Correct |
4 ms |
5332 KB |
Output is correct |
6 |
Correct |
4 ms |
5332 KB |
Output is correct |
7 |
Correct |
4 ms |
5332 KB |
Output is correct |
8 |
Correct |
5 ms |
5332 KB |
Output is correct |
9 |
Correct |
4 ms |
5332 KB |
Output is correct |
10 |
Correct |
4 ms |
5252 KB |
Output is correct |
11 |
Correct |
4 ms |
5308 KB |
Output is correct |
12 |
Correct |
4 ms |
5284 KB |
Output is correct |
13 |
Correct |
4 ms |
5260 KB |
Output is correct |
14 |
Correct |
4 ms |
5288 KB |
Output is correct |
15 |
Correct |
4 ms |
5204 KB |
Output is correct |
16 |
Correct |
3 ms |
5204 KB |
Output is correct |
17 |
Correct |
4 ms |
5332 KB |
Output is correct |
18 |
Correct |
4 ms |
5332 KB |
Output is correct |
19 |
Correct |
4 ms |
5332 KB |
Output is correct |
20 |
Correct |
3 ms |
5332 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
232 ms |
31092 KB |
Output is correct |
2 |
Correct |
238 ms |
31180 KB |
Output is correct |
3 |
Correct |
223 ms |
31096 KB |
Output is correct |
4 |
Correct |
237 ms |
31180 KB |
Output is correct |
5 |
Correct |
218 ms |
31076 KB |
Output is correct |
6 |
Correct |
241 ms |
36004 KB |
Output is correct |
7 |
Correct |
282 ms |
34892 KB |
Output is correct |
8 |
Correct |
262 ms |
33772 KB |
Output is correct |
9 |
Correct |
233 ms |
32820 KB |
Output is correct |
10 |
Correct |
246 ms |
31156 KB |
Output is correct |
11 |
Correct |
219 ms |
31440 KB |
Output is correct |
12 |
Correct |
210 ms |
31456 KB |
Output is correct |
13 |
Correct |
252 ms |
31344 KB |
Output is correct |
14 |
Correct |
198 ms |
29468 KB |
Output is correct |
15 |
Correct |
167 ms |
27492 KB |
Output is correct |
16 |
Correct |
105 ms |
21432 KB |
Output is correct |
17 |
Correct |
170 ms |
31092 KB |
Output is correct |
18 |
Correct |
197 ms |
31192 KB |
Output is correct |
19 |
Correct |
203 ms |
31188 KB |
Output is correct |
20 |
Correct |
191 ms |
31156 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
4 ms |
5204 KB |
Output is correct |
2 |
Correct |
3 ms |
5204 KB |
Output is correct |
3 |
Correct |
4 ms |
5204 KB |
Output is correct |
4 |
Correct |
4 ms |
5204 KB |
Output is correct |
5 |
Correct |
3 ms |
5076 KB |
Output is correct |
6 |
Correct |
4 ms |
5076 KB |
Output is correct |
7 |
Correct |
3 ms |
5076 KB |
Output is correct |
8 |
Correct |
4 ms |
5076 KB |
Output is correct |
9 |
Correct |
3 ms |
5076 KB |
Output is correct |
10 |
Correct |
3 ms |
5076 KB |
Output is correct |
11 |
Correct |
3 ms |
5076 KB |
Output is correct |
12 |
Correct |
3 ms |
5176 KB |
Output is correct |
13 |
Correct |
5 ms |
5204 KB |
Output is correct |
14 |
Correct |
3 ms |
5204 KB |
Output is correct |
15 |
Correct |
4 ms |
5204 KB |
Output is correct |
16 |
Correct |
3 ms |
5204 KB |
Output is correct |
17 |
Correct |
4 ms |
5204 KB |
Output is correct |
18 |
Correct |
3 ms |
5176 KB |
Output is correct |
19 |
Correct |
3 ms |
5076 KB |
Output is correct |
20 |
Correct |
3 ms |
5076 KB |
Output is correct |
21 |
Correct |
4 ms |
5204 KB |
Output is correct |
22 |
Correct |
4 ms |
5176 KB |
Output is correct |
23 |
Correct |
3 ms |
5204 KB |
Output is correct |
24 |
Correct |
3 ms |
5204 KB |
Output is correct |
25 |
Correct |
3 ms |
5036 KB |
Output is correct |
26 |
Correct |
3 ms |
5076 KB |
Output is correct |
27 |
Correct |
3 ms |
5076 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
207 ms |
31092 KB |
Output is correct |
2 |
Correct |
210 ms |
30972 KB |
Output is correct |
3 |
Correct |
188 ms |
26024 KB |
Output is correct |
4 |
Correct |
166 ms |
20636 KB |
Output is correct |
5 |
Correct |
102 ms |
16376 KB |
Output is correct |
6 |
Correct |
104 ms |
14988 KB |
Output is correct |
7 |
Correct |
85 ms |
14216 KB |
Output is correct |
8 |
Correct |
82 ms |
13436 KB |
Output is correct |
9 |
Correct |
96 ms |
12948 KB |
Output is correct |
10 |
Correct |
78 ms |
12736 KB |
Output is correct |
11 |
Correct |
62 ms |
12388 KB |
Output is correct |
12 |
Correct |
63 ms |
12252 KB |
Output is correct |
13 |
Correct |
59 ms |
12312 KB |
Output is correct |
14 |
Correct |
63 ms |
14804 KB |
Output is correct |
15 |
Correct |
200 ms |
30392 KB |
Output is correct |
16 |
Correct |
197 ms |
28856 KB |
Output is correct |
17 |
Correct |
177 ms |
26952 KB |
Output is correct |
18 |
Correct |
170 ms |
25400 KB |
Output is correct |
19 |
Correct |
151 ms |
20684 KB |
Output is correct |
20 |
Correct |
141 ms |
20728 KB |
Output is correct |
21 |
Correct |
154 ms |
20696 KB |
Output is correct |
22 |
Correct |
118 ms |
18632 KB |
Output is correct |
23 |
Correct |
87 ms |
16552 KB |
Output is correct |
24 |
Correct |
161 ms |
25756 KB |
Output is correct |
25 |
Correct |
176 ms |
25768 KB |
Output is correct |
26 |
Correct |
146 ms |
22512 KB |
Output is correct |
27 |
Correct |
152 ms |
22440 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Correct |
3 ms |
4948 KB |
Output is correct |
3 |
Correct |
3 ms |
4948 KB |
Output is correct |
4 |
Correct |
3 ms |
4948 KB |
Output is correct |
5 |
Correct |
3 ms |
5004 KB |
Output is correct |
6 |
Correct |
3 ms |
4948 KB |
Output is correct |
7 |
Correct |
3 ms |
4948 KB |
Output is correct |
8 |
Incorrect |
3 ms |
4948 KB |
Output isn't correct |
9 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
4948 KB |
Output is correct |
2 |
Correct |
3 ms |
4948 KB |
Output is correct |
3 |
Correct |
3 ms |
4948 KB |
Output is correct |
4 |
Correct |
3 ms |
4948 KB |
Output is correct |
5 |
Correct |
3 ms |
5004 KB |
Output is correct |
6 |
Correct |
3 ms |
4948 KB |
Output is correct |
7 |
Correct |
3 ms |
4948 KB |
Output is correct |
8 |
Incorrect |
3 ms |
4948 KB |
Output isn't correct |
9 |
Halted |
0 ms |
0 KB |
- |