/* made by amunduzbaev */
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
#include "bits/stdc++.h"
using namespace std;
//using namespace __gnu_pbds;
#define ff first
#define ss second
#define pb push_back
#define mp make_pair
#define ub upper_bound
#define lb lower_bound
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define rall(x) x.rbegin(),x.rend()
#define NeedForSpeed ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define vv vector
#define tut(x) array<int, x>
typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef vector<int> vii;
typedef vector<pii> vpii;
template<class T> bool umin(T& a, const T& b) {return a > b? a = b, true:false;}
template<class T> bool umax(T& a, const T& b) {return a < b? a = b, true:false;}
void usaco(string s) { freopen((s+".in").c_str(),"r",stdin);
freopen((s+".out").c_str(),"w",stdout); NeedForSpeed }
//template<class T> using oset = tree<T,
//null_type, less_equal<T>, rb_tree_tag,
//tree_order_statistics_node_update> ordered_set;
const int MAXN = 2e5+5;
class Articulation {
public:
std::vector<int> keyV, bcc[MAXN];
int cnt;
int gao(int n, const std::vector<int> e[]) {
memset(tag, use = 0, sizeof(tag[0]) * n);
memset(low, cnt = 0, sizeof(low[0]) * n);
std::fill_n(bcc, n, keyV = std::vector<int>());
for (int i = 0; i < n; ++i) if (!tag[i]) dfs(i, 1, e);
return cnt;
}
private:
int tag[MAXN], low[MAXN], dot[MAXN], use;
void dfs(int x, int dep, const std::vector<int> e[]) {
int src = 0, out = 1 < dep; dot[use++] = x;
tag[x] = low[x] = dep;
for (auto &y: e[x]) {
if (!tag[y]) {
dfs(y, dep + 1, e);
low[x] = std::min(low[x], low[y]);
if (low[y] >= tag[x]) {
if (++out == 2) keyV.push_back(x);
while (dot[--use] != y) bcc[dot[use]].push_back(cnt);
bcc[x].push_back(cnt); bcc[y].push_back(cnt++);
}
} else if (tag[y] != tag[x] - 1 || src++) {
low[x] = std::min(low[x], tag[y]);
}
}
}
} bcc;
const int N = 2e5+5;
const int mod = 1e9+7;
const ll inf = 1e18;
const ld Pi = acos(-1);
#define MULTI 0
int n, m, k, s, t, q, ans, res, a[N];
int used[N], sub[N];
vii edges[N];
void dfs(int u, int p = -1){
used[u] = 1;
sub[u] = (u < n);
for(auto x : edges[u]){
if(!used[x]) dfs(x, u), sub[u] += sub[x];
}
} vii cmp;
void ddfs(int u, int p = -1){
used[u] = 1;
if(u >= n) cmp.pb(u);
for(auto x : edges[u]) if(!used[x]) ddfs(x, u);
}
int take_3(int x){
if(x < 3) return 0;
return x * (x - 1) * (x - 2);
}
int take_2(int x){
if(x < 2) return 0;
return x * (x - 1);
}
/*
4 3
1 2
2 3
3 4
4 4
1 2
2 3
3 4
2 4
*/
void solve(int t_case){
cin>>n>>m;
for(int i=0;i<m;i++){
int a, b; cin>>a>>b, a--, b--;
edges[a].pb(b), edges[b].pb(a);
} m = bcc.gao(n, edges);
for(int i=0;i<n;i++){
edges[i].clear();
for(auto x : bcc.bcc[i]) edges[i].pb(x + n), edges[x + n].pb(i);
} vii tt;
for(int i=0;i<n+m;i++){
if(used[i]) continue;
dfs(i), tt.pb(i), res += take_3(sub[i]);
} memset(used, 0, sizeof used);
for(auto rr : tt){
cmp.clear(), ddfs(rr);
for(auto x : cmp){
int group = sz(edges[x]);
for(auto ch : edges[x]){
int T = 0;
if(sub[ch] > sub[x]) T = sub[rr] - sub[ch];
else T = sub[ch] - 1;
res -= (group - 1) * take_2(T);
if(group > 0 && T >= 1) res -= (group - 1) * T * 2;
for(auto rs : edges[ch]){
if(rs == x) continue;
T -= (sz(edges[rs]) - 1);
} res -= take_2(T);
}
}
} cout<<res<<"\n";
}
signed main(){
NeedForSpeed
if(MULTI){
int t; cin>>t;
for(int t_case = 1; t_case <= t; t_case++) solve(t_case);
} else solve(1);
return 0;
}
Compilation message
count_triplets.cpp: In function 'void usaco(std::string)':
count_triplets.cpp:30:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
30 | void usaco(string s) { freopen((s+".in").c_str(),"r",stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
count_triplets.cpp:31:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
31 | freopen((s+".out").c_str(),"w",stdout); NeedForSpeed }
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
8 ms |
10444 KB |
Output is correct |
2 |
Correct |
8 ms |
10492 KB |
Output is correct |
3 |
Correct |
7 ms |
10496 KB |
Output is correct |
4 |
Correct |
8 ms |
10520 KB |
Output is correct |
5 |
Correct |
7 ms |
10492 KB |
Output is correct |
6 |
Correct |
7 ms |
10492 KB |
Output is correct |
7 |
Incorrect |
7 ms |
10444 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
8 ms |
10444 KB |
Output is correct |
2 |
Correct |
8 ms |
10492 KB |
Output is correct |
3 |
Correct |
7 ms |
10496 KB |
Output is correct |
4 |
Correct |
8 ms |
10520 KB |
Output is correct |
5 |
Correct |
7 ms |
10492 KB |
Output is correct |
6 |
Correct |
7 ms |
10492 KB |
Output is correct |
7 |
Incorrect |
7 ms |
10444 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
98 ms |
29572 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
8 ms |
10624 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
176 ms |
23852 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
7 ms |
10572 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Incorrect |
191 ms |
23872 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
8 ms |
10444 KB |
Output is correct |
2 |
Correct |
8 ms |
10492 KB |
Output is correct |
3 |
Correct |
7 ms |
10496 KB |
Output is correct |
4 |
Correct |
8 ms |
10520 KB |
Output is correct |
5 |
Correct |
7 ms |
10492 KB |
Output is correct |
6 |
Correct |
7 ms |
10492 KB |
Output is correct |
7 |
Incorrect |
7 ms |
10444 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
8 ms |
10444 KB |
Output is correct |
2 |
Correct |
8 ms |
10492 KB |
Output is correct |
3 |
Correct |
7 ms |
10496 KB |
Output is correct |
4 |
Correct |
8 ms |
10520 KB |
Output is correct |
5 |
Correct |
7 ms |
10492 KB |
Output is correct |
6 |
Correct |
7 ms |
10492 KB |
Output is correct |
7 |
Incorrect |
7 ms |
10444 KB |
Output isn't correct |
8 |
Halted |
0 ms |
0 KB |
- |