This submission is migrated from previous version of oj.uz, which used different machine for grading. This submission may have different result if resubmitted.
#include <bits/stdc++.h>
using namespace std;
const int N = 1e5 + 7;
int n, m;
vector<pair<int, int>> g[N];
vector<int> gr[N];
int dep[N], low[N];
bool vis[N];
int col[N], cnt;
int sz[N];
long long ans;
int S;
void dfs(int v, int p = -1) {
vis[v] = true;
low[v] = dep[v];
for (auto [u, i] : g[v]) {
if (!vis[u]) {
dep[u] = dep[v] + 1;
dfs(u, i);
low[v] = min(low[v], low[u]);
if (dep[v] <= low[u] || p == -1) {
col[i] = ++cnt;
} else {
col[i] = col[p];
}
} else {
if (i != p) {
low[v] = min(low[v], dep[u]);
if (dep[u] > dep[v]) col[i] = col[p];
}
}
}
}
int get_size(int v, int p = -1) {
sz[v] = v <= n;
for (int u : gr[v]) {
if (u != p) {
sz[v] += get_size(u, v);
}
}
return sz[v];
}
void find_ans(int v, int p = -1) {
vis[v] = true;
for (int u : gr[v]) {
if (u != p)
find_ans(u, v);
}
if (v <= n) {
for (int u : gr[v]) {
if (u == p)
ans -= (long long)(S - sz[v]) * (S - sz[v] - 1);
else
ans -= (long long)sz[u] * (sz[u] - 1);
}
}
}
int main() {
#ifdef LOCAL
freopen("input.txt", "r", stdin);
#endif
ios::sync_with_stdio(false);
cin.tie(0);
cin >> n >> m;
for (int i = 1; i <= m; ++i) {
int u, v;
cin >> u >> v;
g[u].push_back({v, i});
g[v].push_back({u, i});
}
cnt = n;
for (int i = 1; i <= n; ++i) {
if (!vis[i]) {
dep[i] = 0;
dfs(i);
}
}
for (int i = 1; i <= n; ++i) {
vector<int> v;
for (auto [u, i] : g[i])
v.push_back(col[i]);
sort(v.begin(), v.end());
v.erase(unique(v.begin(), v.end()), v.end());
for (int c : v) {
// cout << min(i, c) << " " << max(i, c) << endl;
gr[i].push_back(c);
gr[c].push_back(i);
}
}
for (int i = 1; i <= cnt; ++i) {
if (!vis[i]) {
S = get_size(i);
ans += (long long)S * (S - 1) * (S - 2);
find_ans(i);
}
}
cout << ans << endl;
return 0;
}
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |
# | Verdict | Execution time | Memory | Grader output |
---|
Fetching results... |