#include <bits/stdc++.h>
using namespace std;
const int MAXN = 5001;
const int MOD = 1e4+7;
int deg[MAXN], cnt[MAXN], fact[MAXN];
int fastPow(int a, int b) {
if (b == 0) return 1;
if (b & 1) return (a * fastPow(a, b-1)) % MOD;
return fastPow((a*a)%MOD, b/2);
}
int rev(int a) {
return fastPow(a, MOD-2);
}
int choose(int a, int b) {
return (((fact[a]*rev(fact[a-b])) % MOD) * rev(fact[b])) % MOD;
}
int main()
{
fact[0] = 1;
for (int i = 1; i<MAXN; ++i) fact[i] = (i*fact[i-1]) % MOD;
int n, m = 0; cin >> n;
for (int i = 0; i<n; ++i) {
int sz,a; cin >> sz;
deg[i] = sz; ++cnt[sz];
m += sz;
while (sz--) {
cin >> a;
}
}
m /= 2;
sort(deg,deg+n);
int same = 1, degSum = 0, x = 1, ans = 0;
for (int i = n-1; i; --i, ++x) {
if (i != n-1) {
if (deg[i] == deg[i+1]) ++same;
else same = 1;
}
degSum += deg[i];
if (degSum - (x*(x-1))/2 == m) {
ans += choose(cnt[deg[i]], same);
}
}
cout << ans;
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
344 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
0 ms |
348 KB |
Output is correct |
4 |
Correct |
0 ms |
348 KB |
Output is correct |
5 |
Correct |
0 ms |
456 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
0 ms |
348 KB |
Output is correct |
2 |
Correct |
0 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
352 KB |
Output is correct |
2 |
Correct |
1 ms |
348 KB |
Output is correct |
3 |
Correct |
1 ms |
348 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1 ms |
352 KB |
Output is correct |
2 |
Correct |
3 ms |
484 KB |
Output is correct |
3 |
Correct |
2 ms |
348 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
3 ms |
344 KB |
Output is correct |
2 |
Correct |
5 ms |
604 KB |
Output is correct |
3 |
Correct |
4 ms |
356 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
8 ms |
732 KB |
Output is correct |
2 |
Correct |
90 ms |
2856 KB |
Output is correct |
3 |
Correct |
1153 ms |
13608 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
14 ms |
860 KB |
Output is correct |
2 |
Correct |
116 ms |
4176 KB |
Output is correct |
3 |
Correct |
541 ms |
18084 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
92 ms |
3104 KB |
Output is correct |
2 |
Correct |
263 ms |
9044 KB |
Output is correct |
3 |
Correct |
884 ms |
29484 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
145 ms |
4948 KB |
Output is correct |
2 |
Correct |
632 ms |
20564 KB |
Output is correct |
3 |
Correct |
2061 ms |
69168 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
1391 ms |
47784 KB |
Output is correct |
2 |
Correct |
904 ms |
31272 KB |
Output is correct |
3 |
Execution timed out |
3049 ms |
103464 KB |
Time limit exceeded |
4 |
Halted |
0 ms |
0 KB |
- |