#include <bits/stdc++.h>
#define pb push_back
#define endl "\n"
#define mp make_pair
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define fname ""
#define sz(x) (int)(x.size())
typedef long long ll;
using namespace std;
const ll N = 5020;
const ll INF = (ll)(1e9);
const ll mod = (ll)(1e9) + 7;
const double eps = 1e-9;
int d[N][N][2], n, m, mx, sum;
vector <int> v[N];
queue <int> q;
void fmbfs(int s) {
for (int i = 1; i <= n; ++i) d[s][i][1] = 0, d[s][i][0] = -1;
q.push(s);
d[s][s][0] = 0; d[s][s][1] = 1;
while (!q.empty()) {
int x = q.front();
q.pop();
for (int j = 0; j < sz(v[x]); ++j) {
int to = v[x][j];
if (d[s][to][0] == -1) {
d[s][to][0] = d[s][x][0] + 1;
d[s][to][1] += d[s][x][1];
q.push(to);
continue;
}
if (d[s][to][0] == d[s][x][0] + 1) {
d[s][to][1] += d[s][x][1];
}
}
}
for (int i = 1; i <= n; ++i) {
mx = max(mx, d[s][i][0]);
}
}
int main () {
//freopen(fname".in", "r", stdin);
//freopen(fname".out", "w", stdout);
scanf("%lld", &n);
for (int i = 1; i <= n; ++i) {
ll x, y; scanf("%lld%lld", &x, &y);
v[x].pb(y); v[y].pb(x);
}
for (int i = 1; i <= n; ++i) {
fmbfs(i);
}
for (int i = 1; i <= n; ++i) {
for (int j = i + 1; j <= n; ++j) {
if (d[i][j][0] == mx) {
sum += d[i][j][1];
}
}
}
printf("%lld", sum);
return 0;
}
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
0 ms |
198720 KB |
Output is correct |
2 |
Correct |
0 ms |
198720 KB |
Output is correct |
3 |
Correct |
0 ms |
198720 KB |
Output is correct |
4 |
Correct |
0 ms |
198720 KB |
Output is correct |
5 |
Correct |
0 ms |
198720 KB |
Output is correct |
6 |
Correct |
0 ms |
198720 KB |
Output is correct |
7 |
Correct |
0 ms |
198720 KB |
Output is correct |
8 |
Correct |
0 ms |
198720 KB |
Output is correct |
9 |
Correct |
0 ms |
198720 KB |
Output is correct |
10 |
Correct |
0 ms |
198720 KB |
Output is correct |
11 |
Correct |
0 ms |
198720 KB |
Output is correct |
12 |
Correct |
0 ms |
198720 KB |
Output is correct |
13 |
Correct |
0 ms |
198720 KB |
Output is correct |
14 |
Correct |
4 ms |
198720 KB |
Output is correct |
15 |
Correct |
4 ms |
198720 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Correct |
8 ms |
198720 KB |
Output is correct |
2 |
Correct |
14 ms |
198720 KB |
Output is correct |
3 |
Correct |
27 ms |
198720 KB |
Output is correct |
4 |
Correct |
22 ms |
198720 KB |
Output is correct |
5 |
Correct |
628 ms |
198852 KB |
Output is correct |
6 |
Correct |
403 ms |
198852 KB |
Output is correct |
7 |
Correct |
667 ms |
198852 KB |
Output is correct |
8 |
Correct |
706 ms |
198852 KB |
Output is correct |
9 |
Correct |
605 ms |
198852 KB |
Output is correct |
10 |
Correct |
664 ms |
198852 KB |
Output is correct |
# |
결과 |
실행 시간 |
메모리 |
Grader output |
1 |
Runtime error |
13 ms |
199376 KB |
SIGSEGV Segmentation fault |
2 |
Runtime error |
0 ms |
199244 KB |
SIGSEGV Segmentation fault |
3 |
Runtime error |
0 ms |
198848 KB |
SIGSEGV Segmentation fault |
4 |
Runtime error |
0 ms |
198848 KB |
SIGSEGV Segmentation fault |
5 |
Runtime error |
2 ms |
198848 KB |
SIGSEGV Segmentation fault |
6 |
Runtime error |
15 ms |
200432 KB |
SIGSEGV Segmentation fault |
7 |
Runtime error |
43 ms |
202676 KB |
SIGSEGV Segmentation fault |
8 |
Runtime error |
2 ms |
198848 KB |
SIGSEGV Segmentation fault |
9 |
Runtime error |
0 ms |
198848 KB |
SIGSEGV Segmentation fault |
10 |
Runtime error |
0 ms |
198848 KB |
SIGSEGV Segmentation fault |
11 |
Runtime error |
0 ms |
205288 KB |
SIGSEGV Segmentation fault |
12 |
Runtime error |
22 ms |
200956 KB |
SIGSEGV Segmentation fault |