#include <bits/stdc++.h>
#define int long long int
#define lli int
#define ld long double
#define pb push_back
#define MP make_pair
#define REP(i, n) for(int i = 0; (i) < (n); (i)++)
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(), x.rend()
using namespace std;
void fastio() {
ios_base::sync_with_stdio(false);
cin.tie(NULL);
}
const int N = 2e5 + 5;
const int INF = 1e9 + 500;
int n, m;
vector<vector<array<int, 2> > > adj(N, vector<array<int, 2> >());
int tim = 0;
vector<int> tin(N, -1), low(N, 0);
vector<array<int, 2> > edg(N);
vector<bool> isBr(N, 0);
vector<int> comp(N, -1), cmpsz(N, 0);
vector<vector<int> > cadj(N, vector<int>());
vector<int> subsz(N, 0);
vector<int> rt;
vector<int> vis(N, 0);
lli ans = 0;
void find_bridge(int node, int par) {
tin[node] = low[node] = tim++;
for(auto c : adj[node]) {
if(c[0] == par) {
continue;
}
if(tin[c[0]] != -1) {
low[node] = min(low[node], tin[c[0]]);
}
else {
find_bridge(c[0], node);
low[node] = min(low[node], low[c[0]]);
// cout << "c[1]:" << c[1] << " node:" << node << " lowc0:" << low[c[0]] << " tin[node]:" << tin[node] << "\n";
if(low[c[0]] > tin[node]) {
//bridge
isBr[c[1]] = 1;
}
}
}
}
void get_comp(int node, int cm) {
comp[node] = cm;
cmpsz[cm]++;
for(auto c : adj[node]) {
if(comp[c[0]] != -1 || isBr[c[1]]) continue;
get_comp(c[0], cm);
}
}
void prec(int node, int par) {
subsz[node] = cmpsz[node];
for(auto c : cadj[node]) {
if(c == par) continue;
prec(c, node);
subsz[node] += subsz[c];
}
}
void dfs(int node, int par, int root) {
// cout << "node:" << node << "\n";
lli ret = 0;
lli x = subsz[root] - cmpsz[node];
for(auto c : cadj[node]) {
if(c == par) {
int sbt = subsz[root] - subsz[node];
ret += 1ll * cmpsz[node] * sbt * (x - sbt);
continue;
}
int sbt = subsz[c];
ret += 1ll * cmpsz[node] * sbt * (x - sbt);
dfs(c, node, root);
}
// cout << "node: " << node << " ret:" << ret << "\n";
ans += ret;
}
void dfs2(int node, int par, int root) {
// cout << "node:" << node << "\n";
int conn = 0;
vis[node] = 1;
for(auto c : adj[node]) {
if(!isBr[c[1]]) {
if(vis[c[0]]) continue;
dfs2(c[0], node, root);
continue;
}
if(c[0] == par) {
conn += subsz[root] - subsz[comp[node]];
continue;
}
conn += subsz[comp[c[0]]];
dfs2(c[0], node, root);
}
if(cmpsz[comp[node]] < 2) return;
// cout << "node:" << node << "conn: " << conn << "\n";
// cout << "add : " << 2ll * (cmpsz[comp[node]] - 1) * (subsz[root] - conn - cmpsz[comp[node]]) << "\n";
for(auto c : adj[node]) {
if(!isBr[c[1]]) continue;
int sbt;
if(c[0] == par) {
sbt = subsz[root] - subsz[comp[node]];
}
else {
sbt = subsz[comp[c[0]]];
}
ans -= 1ll * (comp[node] - 1) * sbt * (conn - sbt);
}
ans += 2ll * (cmpsz[comp[node]] - 1) * (subsz[root] - conn - cmpsz[comp[node]]);
}
void solve() {
cin >> n >> m;
REP(i, m) {
int u, v;
cin >> u >> v;
edg[i] = {u, v};
adj[u].pb({v, i});
adj[v].pb({u, i});
}
for(int i = 1; i <= n; i++) {
if(tin[i] != -1) continue;
rt.pb(i);
find_bridge(i, 0);
}
int cur = 1;
for(int i = 1; i <= n; i++) {
if(comp[i] == -1) {
get_comp(i, cur++);
}
// cout << "i:" << i << " comp:" << comp[i] << "\n";
}
for(int i = 0; i < m; i++) {
if(isBr[i]) {
// cout << edg[i][0] << " " << edg[i][1] << endl;
cadj[comp[edg[i][0]]].pb(comp[edg[i][1]]);
cadj[comp[edg[i][1]]].pb(comp[edg[i][0]]);
}
}
for(auto c : rt) {
prec(comp[c], 0);
}
for(int i = 1; i < cur; i++) {
ans += 1ll * cmpsz[i] * (cmpsz[i] - 1) * (cmpsz[i] - 2);
}
// cout << "ans: " << ans << "\n";
for(int c : rt) {
dfs(comp[c], 0, comp[c]);
}
// cout << "ans:" << ans << "\n";
for(int c : rt) {
dfs2(c, 0, comp[c]);
}
cout << ans << "\n";
}
signed main() {
fastio();
solve();
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
22360 KB |
Output is correct |
2 |
Correct |
10 ms |
22364 KB |
Output is correct |
3 |
Correct |
9 ms |
22364 KB |
Output is correct |
4 |
Correct |
9 ms |
22364 KB |
Output is correct |
5 |
Correct |
9 ms |
22364 KB |
Output is correct |
6 |
Correct |
8 ms |
22168 KB |
Output is correct |
7 |
Incorrect |
7 ms |
22264 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
22360 KB |
Output is correct |
2 |
Correct |
10 ms |
22364 KB |
Output is correct |
3 |
Correct |
9 ms |
22364 KB |
Output is correct |
4 |
Correct |
9 ms |
22364 KB |
Output is correct |
5 |
Correct |
9 ms |
22364 KB |
Output is correct |
6 |
Correct |
8 ms |
22168 KB |
Output is correct |
7 |
Incorrect |
7 ms |
22264 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
74 ms |
37004 KB |
Output is correct |
2 |
Correct |
70 ms |
36836 KB |
Output is correct |
3 |
Correct |
95 ms |
33356 KB |
Output is correct |
4 |
Correct |
67 ms |
35096 KB |
Output is correct |
5 |
Correct |
76 ms |
31584 KB |
Output is correct |
6 |
Correct |
78 ms |
32040 KB |
Output is correct |
7 |
Correct |
67 ms |
30992 KB |
Output is correct |
8 |
Correct |
98 ms |
31600 KB |
Output is correct |
9 |
Correct |
67 ms |
29944 KB |
Output is correct |
10 |
Correct |
66 ms |
30544 KB |
Output is correct |
11 |
Correct |
55 ms |
28388 KB |
Output is correct |
12 |
Correct |
62 ms |
28364 KB |
Output is correct |
13 |
Correct |
56 ms |
28364 KB |
Output is correct |
14 |
Correct |
59 ms |
28096 KB |
Output is correct |
15 |
Correct |
52 ms |
27692 KB |
Output is correct |
16 |
Correct |
56 ms |
27420 KB |
Output is correct |
17 |
Correct |
11 ms |
23508 KB |
Output is correct |
18 |
Correct |
13 ms |
23508 KB |
Output is correct |
19 |
Correct |
12 ms |
23508 KB |
Output is correct |
20 |
Correct |
14 ms |
23344 KB |
Output is correct |
21 |
Correct |
13 ms |
23508 KB |
Output is correct |
22 |
Correct |
13 ms |
23508 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
11 ms |
22364 KB |
Output is correct |
2 |
Correct |
10 ms |
22396 KB |
Output is correct |
3 |
Correct |
10 ms |
22360 KB |
Output is correct |
4 |
Correct |
8 ms |
22360 KB |
Output is correct |
5 |
Correct |
10 ms |
22364 KB |
Output is correct |
6 |
Correct |
10 ms |
22376 KB |
Output is correct |
7 |
Correct |
8 ms |
22364 KB |
Output is correct |
8 |
Correct |
10 ms |
22520 KB |
Output is correct |
9 |
Correct |
9 ms |
22364 KB |
Output is correct |
10 |
Correct |
9 ms |
22364 KB |
Output is correct |
11 |
Correct |
11 ms |
22364 KB |
Output is correct |
12 |
Correct |
9 ms |
22364 KB |
Output is correct |
13 |
Correct |
8 ms |
22364 KB |
Output is correct |
14 |
Correct |
9 ms |
22364 KB |
Output is correct |
15 |
Correct |
10 ms |
22364 KB |
Output is correct |
16 |
Correct |
8 ms |
22364 KB |
Output is correct |
17 |
Correct |
9 ms |
22364 KB |
Output is correct |
18 |
Correct |
9 ms |
22364 KB |
Output is correct |
19 |
Correct |
8 ms |
22364 KB |
Output is correct |
20 |
Correct |
9 ms |
22364 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
75 ms |
31200 KB |
Output is correct |
2 |
Correct |
85 ms |
31056 KB |
Output is correct |
3 |
Correct |
77 ms |
31060 KB |
Output is correct |
4 |
Correct |
79 ms |
31056 KB |
Output is correct |
5 |
Correct |
74 ms |
31056 KB |
Output is correct |
6 |
Correct |
123 ms |
35584 KB |
Output is correct |
7 |
Correct |
86 ms |
34456 KB |
Output is correct |
8 |
Correct |
87 ms |
33620 KB |
Output is correct |
9 |
Correct |
94 ms |
32596 KB |
Output is correct |
10 |
Correct |
88 ms |
31056 KB |
Output is correct |
11 |
Correct |
76 ms |
31276 KB |
Output is correct |
12 |
Correct |
81 ms |
31060 KB |
Output is correct |
13 |
Correct |
73 ms |
31060 KB |
Output is correct |
14 |
Correct |
66 ms |
30548 KB |
Output is correct |
15 |
Correct |
61 ms |
29920 KB |
Output is correct |
16 |
Correct |
51 ms |
28200 KB |
Output is correct |
17 |
Correct |
53 ms |
30916 KB |
Output is correct |
18 |
Correct |
56 ms |
31044 KB |
Output is correct |
19 |
Correct |
52 ms |
31660 KB |
Output is correct |
20 |
Correct |
51 ms |
31024 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
9 ms |
22424 KB |
Output is correct |
2 |
Correct |
9 ms |
22300 KB |
Output is correct |
3 |
Incorrect |
8 ms |
22364 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
82 ms |
31040 KB |
Output is correct |
2 |
Correct |
75 ms |
31060 KB |
Output is correct |
3 |
Incorrect |
81 ms |
30804 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
22360 KB |
Output is correct |
2 |
Correct |
10 ms |
22364 KB |
Output is correct |
3 |
Correct |
9 ms |
22364 KB |
Output is correct |
4 |
Correct |
9 ms |
22364 KB |
Output is correct |
5 |
Correct |
9 ms |
22364 KB |
Output is correct |
6 |
Correct |
8 ms |
22168 KB |
Output is correct |
7 |
Incorrect |
7 ms |
22264 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
22360 KB |
Output is correct |
2 |
Correct |
10 ms |
22364 KB |
Output is correct |
3 |
Correct |
9 ms |
22364 KB |
Output is correct |
4 |
Correct |
9 ms |
22364 KB |
Output is correct |
5 |
Correct |
9 ms |
22364 KB |
Output is correct |
6 |
Correct |
8 ms |
22168 KB |
Output is correct |
7 |
Incorrect |
7 ms |
22264 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |