#include <bits/stdc++.h>
using namespace std;
int32_t MOD = 1e9 + 7;
struct modint
{
int32_t value;
modint() = default;
modint(int32_t value_) : value(value_ % MOD) {}
modint(int64_t value_) : value(value_ % MOD) {}
inline modint operator+(modint other) const
{
int32_t c = this->value + other.value;
return modint(c >= MOD ? c - MOD : c);
}
inline modint operator-(modint other) const
{
int32_t c = this->value - other.value;
return modint(c < 0 ? c + MOD : c);
}
inline modint operator*(modint other) const
{
int32_t c = (int64_t)this->value * other.value % MOD;
return modint(c < 0 ? c + MOD : c);
}
inline modint &operator+=(modint other)
{
this->value += other.value;
if (this->value >= MOD)
this->value -= MOD;
return *this;
}
inline modint &operator-=(modint other)
{
this->value -= other.value;
if (this->value < 0)
this->value += MOD;
return *this;
}
inline modint &operator*=(modint other)
{
this->value = (int64_t)this->value * other.value % MOD;
if (this->value < 0)
this->value += MOD;
return *this;
}
inline modint operator-() const { return modint(this->value ? MOD - this->value : 0); }
modint pow(int32_t k) const
{
modint x = *this, y = 1;
for (; k; k >>= 1)
{
if (k & 1)
y *= x;
x *= x;
}
return y;
}
modint inv() const { return pow(MOD - 2); } // MOD must be a prime
inline modint operator/(modint other) const { return *this * other.inv(); }
inline modint operator/=(modint other) { return *this *= other.inv(); }
inline bool operator==(modint other) const { return value == other.value; }
inline bool operator!=(modint other) const { return value != other.value; }
inline bool operator<(modint other) const { return value < other.value; }
inline bool operator>(modint other) const { return value > other.value; }
};
modint operator*(int64_t value, modint n) { return modint(value) * n; }
modint operator*(int32_t value, modint n) { return modint(value) * n; }
istream &operator>>(istream &in, modint &n) { return in >> n.value; }
ostream &operator<<(ostream &out, modint n) { return out << n.value; }
struct combi
{
int n;
vector<modint> facts, finvs, invs;
combi(int _n) : n(_n), facts(_n), finvs(_n), invs(_n)
{
facts[0] = finvs[0] = 1;
invs[1] = 1;
for (int i = 2; i < n; i++)
invs[i] = invs[MOD % i] * (-MOD / i);
for (int i = 1; i < n; i++)
{
facts[i] = facts[i - 1] * i;
finvs[i] = finvs[i - 1] * invs[i];
}
}
inline modint fact(int n) { return facts[n]; }
inline modint finv(int n) { return finvs[n]; }
inline modint inv(int n) { return invs[n]; }
inline modint ncr(int n, int k) { return n < k or k < 0 ? 0 : facts[n] * finvs[k] * finvs[n - k]; }
inline modint aranj(int n, int k) { return ncr(n, k) * facts[k]; }
inline modint sb(int n, int k) { return ncr(n + k - 1, n); };
};
combi C(1e6 + 1);
int32_t main()
{
cin.tie(nullptr)->sync_with_stdio(false);
int n, l;
cin >> n >> l;
vector<int> a(n + 1);
for (int i = 1; i <= n; ++i)
{
cin >> a[i];
}
cout << C.fact(n) * C.sb(l - (n - 1) * a[1] - 1, n + 1);
}
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
64 ms |
11988 KB |
Output is correct |
2 |
Correct |
66 ms |
12024 KB |
Output is correct |
3 |
Correct |
66 ms |
12028 KB |
Output is correct |
4 |
Correct |
62 ms |
12024 KB |
Output is correct |
5 |
Correct |
64 ms |
12036 KB |
Output is correct |
6 |
Correct |
62 ms |
12024 KB |
Output is correct |
7 |
Correct |
63 ms |
12028 KB |
Output is correct |
8 |
Correct |
65 ms |
12020 KB |
Output is correct |
9 |
Correct |
64 ms |
11988 KB |
Output is correct |
10 |
Correct |
63 ms |
12020 KB |
Output is correct |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
64 ms |
12024 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Incorrect |
63 ms |
12024 KB |
Output isn't correct |
2 |
Halted |
0 ms |
0 KB |
- |
# |
Verdict |
Execution time |
Memory |
Grader output |
1 |
Correct |
64 ms |
11988 KB |
Output is correct |
2 |
Correct |
66 ms |
12024 KB |
Output is correct |
3 |
Correct |
66 ms |
12028 KB |
Output is correct |
4 |
Correct |
62 ms |
12024 KB |
Output is correct |
5 |
Correct |
64 ms |
12036 KB |
Output is correct |
6 |
Correct |
62 ms |
12024 KB |
Output is correct |
7 |
Correct |
63 ms |
12028 KB |
Output is correct |
8 |
Correct |
65 ms |
12020 KB |
Output is correct |
9 |
Correct |
64 ms |
11988 KB |
Output is correct |
10 |
Correct |
63 ms |
12020 KB |
Output is correct |
11 |
Incorrect |
64 ms |
12024 KB |
Output isn't correct |
12 |
Halted |
0 ms |
0 KB |
- |