#include <iostream>
#include <vector>
using namespace std;
pair<int, int> e[200005];
vector<pair<int, int>> g[100005];
long long int dd[100005], a[100005], b[100005], tin[100005], f[100005], s[100005], z = 0;
vector<int> gg[100005], v;
void dfs(int x, int p) {
tin[x] = f[x] = ++z;
for (auto w : g[x]) {
if (w.first == p) continue;
if (tin[w.first]) {
f[x] = min(f[x], tin[w.first]);
}
else {
dfs(w.first, x);
f[x] = min(f[x], f[w.first]);
if (tin[x] < f[w.first]) {
dd[w.second] = 1;
}
}
}
}
void dfs2(int x, int h) {
b[x] = h;
a[h]++;
for (auto w : g[x]) {
if (b[w.first] || dd[w.second]) continue;
dfs2(w.first, h);
}
}
long long int res = 0, d = 0;
void dfs3(int x, int p) {
v.push_back(x);
s[x] = a[x];
d += a[x];
tin[x] = 1;
long long int h = 0;
for (int w : gg[x]) {
if (w == p) continue;
dfs3(w, x);
s[x] += s[w];
}
}
void dfs4(int x, int p) {
long long int h = 0;
for (int w : gg[x]) {
long long int k;
if (w == p) {
k = d - s[x];
}
else {
dfs4(w, x);
k = s[w];
}
res += h * k;
h += k;
}
}
int main() {
ios::sync_with_stdio(0);
cin.tie(0); cout.tie(0);
int n, m;
cin >> n >> m;
for (int i = 1; i <= m; i++) {
int u, v;
cin >> u >> v;
e[i] = {u, v};
g[u].push_back({v, i});
g[v].push_back({u, i});
}
for (int i = 1; i <= n; i++) {
if (tin[i] == 0) {
dfs(i, -1);
}
}
z = 0;
for (int i = 1; i <= n; i++) {
if (b[i] == 0) {
z++;
dfs2(i, z);
}
}
for (int i = 1; i <= m; i++) {
if (dd[i] == 1) {
gg[b[e[i].first]].push_back(b[e[i].second]);
gg[b[e[i].second]].push_back(b[e[i].first]);
}
}
for (int i = 1; i <= z; i++) tin[i] = 0;
for (int i = 1; i <= z; i++) {
if (tin[i] == 0) {
v.clear();
d = 0;
dfs3(i, -1);
dfs4(i, -1);
for (int w : v) {
//cout << w << " " << a[w] << " " << s[w] << '\n';
res += (a[w] - 1) * a[w] * a[w] / 2;
res += d - a[w];
res += (a[w] - 1) * a[w] * (d - a[w]);
}
}
}
cout << (res - n * (n - 1)) * 2;
}
Compilation message
count_triplets.cpp: In function 'void dfs3(int, int)':
count_triplets.cpp:38:19: warning: unused variable 'h' [-Wunused-variable]
38 | long long int h = 0;
| ^
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
3 ms |
8784 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
3 ms |
8784 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
56 ms |
20872 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
3 ms |
10832 KB |
Output is correct |
2 |
Correct |
4 ms |
10832 KB |
Output is correct |
3 |
Correct |
4 ms |
10832 KB |
Output is correct |
4 |
Correct |
3 ms |
8784 KB |
Output is correct |
5 |
Correct |
3 ms |
8864 KB |
Output is correct |
6 |
Correct |
3 ms |
10832 KB |
Output is correct |
7 |
Correct |
3 ms |
10832 KB |
Output is correct |
8 |
Correct |
3 ms |
10832 KB |
Output is correct |
9 |
Correct |
2 ms |
10912 KB |
Output is correct |
10 |
Incorrect |
3 ms |
10848 KB |
Output isn't correct |
11 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
72 ms |
18500 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
2 ms |
10832 KB |
Output is correct |
2 |
Correct |
3 ms |
8864 KB |
Output is correct |
3 |
Incorrect |
3 ms |
10912 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
68 ms |
18376 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
3 ms |
8784 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
3 ms |
8784 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |