#include <bits/stdc++.h>
#define all(x) x.begin(), x.end()
#define ff first
#define ss second
using namespace std;
typedef long long ll;
typedef pair<int, int> pii;
const int maxn = 2e5+10;
int n;
pii edge[maxn];
int in[maxn], low[maxn], tt;
bool mark_edge[maxn], art[maxn];
int sz_bcc[maxn], sz_comp;
vector<vector<int>> bcc;
vector<int> tree[maxn];
vector<pii> grafo[maxn];
stack<int> stk;
void make_component(int last)
{
bcc.push_back(vector<int>());
while (!stk.empty())
{
int e = stk.top(); stk.pop();
bcc.back().push_back(e);
if (e == last) break;
}
}
void lowlink(int u, bool isroot)
{
in[u] = low[u] = ++tt;
++sz_comp;
bool fwd = 0;
for (auto pp: grafo[u])
{
int v = pp.ff, e = pp.ss;
if (mark_edge[e]) continue;
mark_edge[e] = 1;
stk.push(e);
if (in[v])
{
low[u] = min(low[u], in[v]);
continue;
}
lowlink(v, 0);
low[u] = min(low[u], low[v]);
if (isroot ? fwd : (low[v] >= in[u]))
{
art[u] = 1;
make_component(e);
}
fwd = 1;
}
}
int sub[maxn];
bool vis[maxn];
ll ans, dp[maxn];
ll choose2(int x)
{
return 1ll*x*(x-1)/2ll;
}
ll choose3(int x)
{
return 1ll*x*(x-1)*(x-2);
}
void dfs(int u, int p)
{
vis[u] = 1;
sub[u] = (u <= n ? 1 : sz_bcc[u]);
for (auto v: tree[u])
{
if (v == p) continue;
dfs(v, u);
if (u <= n)
{
dp[u] += 1ll*sub[u]*sub[v];
dp[u] += choose2(sz_bcc[v]);
dp[u] += 1ll*sz_bcc[v]*((ll)tree[v].size()-1);
}
sub[u] += sub[v];
dp[u] += dp[v];
}
}
void solve(int u, int p)
{
for (auto v: tree[u])
ans -= 2ll*(u <= n ? 1 : sz_bcc[u])*dp[v];
for (auto v: tree[u])
{
if (v == p) continue;
int old_sub_v = sub[v], old_sub_u = sub[u];
ll old_dp_v = dp[v], old_dp_u = dp[u];
if (u <= n)
{
int sz = sz_bcc[v];
dp[v] += (dp[u] - dp[v] - 1ll*sub[v]*(sub[u]-sub[v]) - choose2(sz) - 1ll*sz*((ll)tree[v].size()-1));
dp[u] -= (old_dp_v + 1ll*sub[v]*(sub[u]-sub[v]) + choose2(sz) + 1ll*sz*((ll)tree[v].size()-1));
}
else
{
int sz = sz_bcc[u];
dp[v] += (dp[u] - dp[v] + 1ll*sub[v]*(sub[u]-sub[v]) + choose2(sz) + 1ll*sz*((ll)tree[u].size()-1));
dp[u] -= old_dp_v;
}
sub[v] = sub[u];
sub[u] -= old_sub_v;
solve(v, u);
sub[v] = old_sub_v, sub[u] = old_sub_u;
dp[v] = old_dp_v, dp[u] = old_dp_u;
}
}
int main(void)
{
int m;
scanf("%d %d", &n, &m);
for (int i = 1; i <= m; i++)
{
int u, v;
scanf("%d %d", &u, &v);
grafo[u].push_back({v, i});
grafo[v].push_back({u, i});
edge[i] = {u, v};
}
for (int i = 1; i <= n; i++)
{
if (in[i]) continue;
tt = 0;
sz_comp = 0;
int l = bcc.size();
lowlink(i, 1);
make_component(0);
int r = bcc.size();
ans += choose3(sz_comp);
for (int j = l; j < r; j++)
{
vector<int> v;
for (auto e: bcc[j])
{
v.push_back(edge[e].ff);
v.push_back(edge[e].ss);
}
sort(all(v));
v.erase(unique(all(v)), v.end());
for (auto u: v)
{
if (art[u])
{
tree[n+j+1].push_back(u);
tree[u].push_back(n+j+1);
}
else
{
sz_bcc[n+j+1]++;
}
}
}
}
for (int i = 1; i <= 2*n; i++)
{
if (!vis[i] && tree[i].size())
{
dfs(i, 0);
solve(i, 0);
}
}
printf("%lld\n", ans);
}
Compilation message
count_triplets.cpp: In function 'int main()':
count_triplets.cpp:157:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
157 | scanf("%d %d", &n, &m);
| ~~~~~^~~~~~~~~~~~~~~~~
count_triplets.cpp:162:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
162 | scanf("%d %d", &u, &v);
| ~~~~~^~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
9728 KB |
Output is correct |
2 |
Correct |
7 ms |
9708 KB |
Output is correct |
3 |
Correct |
7 ms |
9708 KB |
Output is correct |
4 |
Correct |
7 ms |
9728 KB |
Output is correct |
5 |
Correct |
7 ms |
9728 KB |
Output is correct |
6 |
Correct |
7 ms |
9708 KB |
Output is correct |
7 |
Incorrect |
8 ms |
9708 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
9728 KB |
Output is correct |
2 |
Correct |
7 ms |
9708 KB |
Output is correct |
3 |
Correct |
7 ms |
9708 KB |
Output is correct |
4 |
Correct |
7 ms |
9728 KB |
Output is correct |
5 |
Correct |
7 ms |
9728 KB |
Output is correct |
6 |
Correct |
7 ms |
9708 KB |
Output is correct |
7 |
Incorrect |
8 ms |
9708 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
108 ms |
27624 KB |
Output is correct |
2 |
Correct |
131 ms |
28808 KB |
Output is correct |
3 |
Correct |
148 ms |
34280 KB |
Output is correct |
4 |
Correct |
126 ms |
29780 KB |
Output is correct |
5 |
Correct |
133 ms |
28508 KB |
Output is correct |
6 |
Correct |
164 ms |
33120 KB |
Output is correct |
7 |
Correct |
152 ms |
30624 KB |
Output is correct |
8 |
Correct |
160 ms |
31424 KB |
Output is correct |
9 |
Correct |
182 ms |
27808 KB |
Output is correct |
10 |
Correct |
134 ms |
27424 KB |
Output is correct |
11 |
Correct |
108 ms |
22432 KB |
Output is correct |
12 |
Correct |
110 ms |
22432 KB |
Output is correct |
13 |
Correct |
100 ms |
21728 KB |
Output is correct |
14 |
Correct |
94 ms |
21664 KB |
Output is correct |
15 |
Correct |
64 ms |
20128 KB |
Output is correct |
16 |
Correct |
69 ms |
20128 KB |
Output is correct |
17 |
Correct |
16 ms |
14032 KB |
Output is correct |
18 |
Correct |
16 ms |
13924 KB |
Output is correct |
19 |
Correct |
16 ms |
14048 KB |
Output is correct |
20 |
Correct |
15 ms |
13920 KB |
Output is correct |
21 |
Correct |
13 ms |
13920 KB |
Output is correct |
22 |
Correct |
13 ms |
13920 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
9996 KB |
Output is correct |
2 |
Correct |
7 ms |
9964 KB |
Output is correct |
3 |
Correct |
8 ms |
9964 KB |
Output is correct |
4 |
Correct |
8 ms |
10092 KB |
Output is correct |
5 |
Correct |
8 ms |
10092 KB |
Output is correct |
6 |
Correct |
8 ms |
10092 KB |
Output is correct |
7 |
Correct |
9 ms |
10092 KB |
Output is correct |
8 |
Correct |
8 ms |
10092 KB |
Output is correct |
9 |
Correct |
8 ms |
9964 KB |
Output is correct |
10 |
Correct |
8 ms |
9964 KB |
Output is correct |
11 |
Correct |
8 ms |
9964 KB |
Output is correct |
12 |
Correct |
8 ms |
9964 KB |
Output is correct |
13 |
Correct |
8 ms |
9964 KB |
Output is correct |
14 |
Correct |
9 ms |
9964 KB |
Output is correct |
15 |
Correct |
8 ms |
9836 KB |
Output is correct |
16 |
Correct |
7 ms |
9836 KB |
Output is correct |
17 |
Correct |
8 ms |
9964 KB |
Output is correct |
18 |
Correct |
7 ms |
9964 KB |
Output is correct |
19 |
Correct |
8 ms |
9964 KB |
Output is correct |
20 |
Correct |
8 ms |
9964 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
140 ms |
28444 KB |
Output is correct |
2 |
Correct |
148 ms |
28572 KB |
Output is correct |
3 |
Correct |
170 ms |
28572 KB |
Output is correct |
4 |
Correct |
155 ms |
28572 KB |
Output is correct |
5 |
Correct |
137 ms |
28444 KB |
Output is correct |
6 |
Correct |
188 ms |
42652 KB |
Output is correct |
7 |
Correct |
174 ms |
38044 KB |
Output is correct |
8 |
Correct |
163 ms |
37272 KB |
Output is correct |
9 |
Correct |
169 ms |
34332 KB |
Output is correct |
10 |
Correct |
169 ms |
28592 KB |
Output is correct |
11 |
Correct |
150 ms |
28456 KB |
Output is correct |
12 |
Correct |
151 ms |
28444 KB |
Output is correct |
13 |
Correct |
145 ms |
28444 KB |
Output is correct |
14 |
Correct |
140 ms |
27036 KB |
Output is correct |
15 |
Correct |
141 ms |
25500 KB |
Output is correct |
16 |
Correct |
75 ms |
21148 KB |
Output is correct |
17 |
Correct |
87 ms |
26004 KB |
Output is correct |
18 |
Correct |
84 ms |
26064 KB |
Output is correct |
19 |
Correct |
91 ms |
26184 KB |
Output is correct |
20 |
Correct |
93 ms |
26124 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
9964 KB |
Output is correct |
2 |
Correct |
7 ms |
9964 KB |
Output is correct |
3 |
Incorrect |
8 ms |
9964 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
141 ms |
28444 KB |
Output is correct |
2 |
Correct |
151 ms |
28628 KB |
Output is correct |
3 |
Incorrect |
150 ms |
27104 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
9728 KB |
Output is correct |
2 |
Correct |
7 ms |
9708 KB |
Output is correct |
3 |
Correct |
7 ms |
9708 KB |
Output is correct |
4 |
Correct |
7 ms |
9728 KB |
Output is correct |
5 |
Correct |
7 ms |
9728 KB |
Output is correct |
6 |
Correct |
7 ms |
9708 KB |
Output is correct |
7 |
Incorrect |
8 ms |
9708 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
7 ms |
9728 KB |
Output is correct |
2 |
Correct |
7 ms |
9708 KB |
Output is correct |
3 |
Correct |
7 ms |
9708 KB |
Output is correct |
4 |
Correct |
7 ms |
9728 KB |
Output is correct |
5 |
Correct |
7 ms |
9728 KB |
Output is correct |
6 |
Correct |
7 ms |
9708 KB |
Output is correct |
7 |
Incorrect |
8 ms |
9708 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |