#include <stdio.h>
#define N 100007
#define M 400007
int n, m, to[M], nx[M], st[N], low[N], vis[N], ts, stk[N], instack[N], *top = &stk[0];
int bto[N * 4], bnx[N * 4], bst[N * 2], b, bm, bsz[N * 2];
long long ans = 0;
inline int min(int i, int j) { return i < j ? i : j; }
inline void minimize(int &i, int j) { (i < j ? i = j : 0); }
void build(int u, int p)
{
low[u] = vis[u] = ++ts;
instack[*(++top) = u] = 1;
int i, v, a = 0, c = 0;
for (i = st[u]; i; i = nx[i]) if (to[i] != p) {
v = to[i];
if (!vis[v]) {
++c;
build(v, u);
if (low[v] >= vis[u]) a = 1;
low[u] = min(low[u], low[v]);
} else if (instack[v]) {
low[u] = min(low[u], vis[v]);
}
}
if (a) {
++b;
bool cont = true;
while (cont) {
instack[v = (*top--)] = 0;
cont = (v != u);
++bm, bnx[bm] = bst[v], bto[bst[v] = bm] = b;
++bm, bnx[bm] = bst[b], bto[bst[b] = bm] = v;
}
instack[(*++top) = u] = 1;
}
}
void solve(int u, int p)
{
int i, v, d = 0;
long long x = 0;
bsz[u] = (u <= n);
for (i = bst[u]; i; i = bnx[i]) if (bto[i] != p) {
solve(v = bto[i], u), bsz[u] += bsz[v], ++d;
x += (long long) bsz[v] * (bsz[v] - 1);
}
if (u > n) {
x += (long long) (n - bsz[u]) * (n - bsz[u] - 1);
ans -= x * d;
}
}
int main()
{
int i, u, v;
scanf("%d %d", &n, &m);
for (i = 1; i <= m; ++i) {
scanf("%d %d", &u, &v);
nx[i * 2] = st[u], to[st[u] = i * 2] = v;
nx[i * 2 - 1] = st[v], to[st[v] = i * 2 - 1] = u;
}
b = n, build(1, 0);
ans = (long long) n * (n - 1) * (n - 2), solve(1, 0);
printf("%lld", ans);
}
Compilation message
count_triplets.cpp: In function 'int main()':
count_triplets.cpp:63:7: 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:65:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
scanf("%d %d", &u, &v);
~~~~~^~~~~~~~~~~~~~~~~
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Correct |
50 ms |
15236 KB |
Output is correct |
| 2 |
Correct |
51 ms |
15224 KB |
Output is correct |
| 3 |
Incorrect |
49 ms |
10364 KB |
Output isn't correct |
| 4 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
56 ms |
8312 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
50 ms |
8184 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
Verdict |
Execution time |
Memory |
Grader output |
| 1 |
Incorrect |
5 ms |
384 KB |
Output isn't correct |
| 2 |
Halted |
0 ms |
0 KB |
- |
