#include <bits/stdc++.h>
using namespace std;
typedef pair<int, int> pii;
typedef long long LL;
vector<pii> g[100005];
set<int> gs[100005];
bool idx[200005];
int low[100005], vis[100005], p[100005], sz[100005], T = 1;
void dfs1(int u, int p){
vis[u] = low[u] = T++;
for(int i=0;i<g[u].size();i++){
int v = g[u][i].first;
if(v == p) continue;
if(vis[v]) low[u] = min(low[u], vis[v]);
else{
dfs1(v, u);
low[u] = min(low[u], low[v]);
if(low[v] > vis[u]) idx[g[u][i].second] = 1;
}
}
}
int root(int a){
while(p[a] != a){
p[a] = p[p[a]];
a = p[a];
}
return a;
}
bool merge(int a, int b){
a = root(a), b = root(b);
if(a == b) return 0;
sz[b] += sz[a];
p[a] = b;
return 1;
}
LL s[100005], sc[100005];
LL ans = 0;
void dfs2(int u, int p){
for(set<int>::iterator its=gs[u].begin();its != gs[u].end();its++){
int v = *its;
if(v == p) continue;
dfs2(v, u);
ans += (LL)sc[v]*sz[u]; // f
if(sz[u] > 1) ans += (LL)s[v]*(sz[u]-1 + (LL)(sz[u]-1)*(sz[u]-2)); // cf
ans += (LL)sc[v]*s[u]; // f
ans += (LL)s[v]*sc[u]; // cf
s[u] += s[v];
sc[u] += sc[v];
sc[u] += (LL)s[v]*sz[u];
}
s[u] += sz[u];
sc[u] += (LL)sz[u]*(sz[u]-1);
}
int main(){
int n, m;
scanf("%d%d", &n, &m);
for(int i=0;i<m;i++){
int a, b;
scanf("%d%d", &a, &b);
g[a].push_back(pii(b, i));
g[b].push_back(pii(a, i));
}
dfs1(1, 0);
for(int i=1;i<=n;i++) p[i] = i, sz[i] = 1;
for(int i=1;i<=n;i++){
for(int j=0;j<g[i].size();j++){
int v = g[i][j].first, edge = g[i][j].second;
if(!idx[edge]){
merge(i, v);
}
}
}
int r = 0;
for(int i=1;i<=n;i++){
for(int j=0;j<g[i].size();j++){
int v = g[i][j].first, edge = g[i][j].second;
if(!idx[edge]) continue;
if(root(i) == root(v)) continue;
gs[root(i)].insert(root(v));
gs[root(v)].insert(root(i));
}
if(root(i) == i){
r = i;
}
}
dfs2(r, 0);
ans *= 2;
for(int i=1;i<=n;i++){
if(root(i) == i){
ans += (LL)sz[i]*(sz[i]-1)*(sz[i]-2);
}
}
printf("%lld\n", ans);
}
Compilation message
count_triplets.cpp: In function 'void dfs1(int, int)':
count_triplets.cpp:12:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int i=0;i<g[u].size();i++){
~^~~~~~~~~~~~
count_triplets.cpp: In function 'int main()':
count_triplets.cpp:74:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int j=0;j<g[i].size();j++){
~^~~~~~~~~~~~
count_triplets.cpp:83:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int j=0;j<g[i].size();j++){
~^~~~~~~~~~~~
count_triplets.cpp:64:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &n, &m);
~~~~~^~~~~~~~~~~~~~~~
count_triplets.cpp:67:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d%d", &a, &b);
~~~~~^~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
7420 KB |
Output is correct |
2 |
Correct |
10 ms |
7420 KB |
Output is correct |
3 |
Correct |
9 ms |
7460 KB |
Output is correct |
4 |
Correct |
9 ms |
7480 KB |
Output is correct |
5 |
Correct |
9 ms |
7484 KB |
Output is correct |
6 |
Correct |
9 ms |
7588 KB |
Output is correct |
7 |
Incorrect |
9 ms |
7588 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
7420 KB |
Output is correct |
2 |
Correct |
10 ms |
7420 KB |
Output is correct |
3 |
Correct |
9 ms |
7460 KB |
Output is correct |
4 |
Correct |
9 ms |
7480 KB |
Output is correct |
5 |
Correct |
9 ms |
7484 KB |
Output is correct |
6 |
Correct |
9 ms |
7588 KB |
Output is correct |
7 |
Incorrect |
9 ms |
7588 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
143 ms |
21332 KB |
Output is correct |
2 |
Correct |
128 ms |
22596 KB |
Output is correct |
3 |
Incorrect |
113 ms |
22596 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
22596 KB |
Output is correct |
2 |
Correct |
11 ms |
22596 KB |
Output is correct |
3 |
Correct |
12 ms |
22596 KB |
Output is correct |
4 |
Correct |
9 ms |
22596 KB |
Output is correct |
5 |
Correct |
10 ms |
22596 KB |
Output is correct |
6 |
Correct |
10 ms |
22596 KB |
Output is correct |
7 |
Correct |
12 ms |
22596 KB |
Output is correct |
8 |
Correct |
10 ms |
22596 KB |
Output is correct |
9 |
Correct |
10 ms |
22596 KB |
Output is correct |
10 |
Incorrect |
9 ms |
22596 KB |
Output isn't correct |
11 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
245 ms |
29252 KB |
Output is correct |
2 |
Correct |
244 ms |
30488 KB |
Output is correct |
3 |
Correct |
235 ms |
31804 KB |
Output is correct |
4 |
Correct |
232 ms |
33048 KB |
Output is correct |
5 |
Correct |
223 ms |
34252 KB |
Output is correct |
6 |
Correct |
264 ms |
41108 KB |
Output is correct |
7 |
Correct |
281 ms |
41108 KB |
Output is correct |
8 |
Correct |
266 ms |
41108 KB |
Output is correct |
9 |
Correct |
229 ms |
41348 KB |
Output is correct |
10 |
Incorrect |
179 ms |
41348 KB |
Output isn't correct |
11 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
9 ms |
41348 KB |
Output is correct |
2 |
Correct |
10 ms |
41348 KB |
Output is correct |
3 |
Incorrect |
9 ms |
41348 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
211 ms |
41828 KB |
Output is correct |
2 |
Correct |
205 ms |
43108 KB |
Output is correct |
3 |
Incorrect |
233 ms |
43108 KB |
Output isn't correct |
4 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
7420 KB |
Output is correct |
2 |
Correct |
10 ms |
7420 KB |
Output is correct |
3 |
Correct |
9 ms |
7460 KB |
Output is correct |
4 |
Correct |
9 ms |
7480 KB |
Output is correct |
5 |
Correct |
9 ms |
7484 KB |
Output is correct |
6 |
Correct |
9 ms |
7588 KB |
Output is correct |
7 |
Incorrect |
9 ms |
7588 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
10 ms |
7420 KB |
Output is correct |
2 |
Correct |
10 ms |
7420 KB |
Output is correct |
3 |
Correct |
9 ms |
7460 KB |
Output is correct |
4 |
Correct |
9 ms |
7480 KB |
Output is correct |
5 |
Correct |
9 ms |
7484 KB |
Output is correct |
6 |
Correct |
9 ms |
7588 KB |
Output is correct |
7 |
Incorrect |
9 ms |
7588 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |