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QOJ
ID | 题目 | 提交者 | 结果 | 用时 | 内存 | 语言 | 文件大小 | 提交时间 | 测评时间 |
---|---|---|---|---|---|---|---|---|---|
#411017 | #8339. Rooted Tree | Errormaker | TL | 1493ms | 6740kb | C++17 | 3.1kb | 2024-05-14 20:11:55 | 2024-05-14 20:11:57 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
const int MOD = 1e9+9;
template <long long P>
struct ModInt
{
public:
ModInt() : v(0) {}
template <typename T>
ModInt(T x) { v = ((long long)x % P + P) % P; }
long long val() const { return v; }
ModInt &operator++()
{
++v;
if (v == P)
v = 0;
return *this;
}
ModInt &operator--()
{
if (v == 0)
v = P;
--v;
return *this;
}
ModInt operator++(int)
{
ModInt oldVal = *this;
++*this;
return oldVal;
}
ModInt operator--(int)
{
ModInt oldVal = *this;
--*this;
return oldVal;
}
ModInt &operator+=(const ModInt &rhs)
{
v += rhs.v;
v %= P;
return *this;
}
ModInt &operator-=(const ModInt &rhs)
{
v -= rhs.v;
v = (v + P) % P;
return *this;
}
ModInt &operator*=(const ModInt &rhs)
{
v *= rhs.v;
v %= P;
return *this;
}
ModInt &operator/=(const ModInt &rhs) { return *this = *this * rhs.inv(); }
ModInt operator+() const { return *this; }
ModInt operator-() const { return ModInt() - *this; }
ModInt pow(long long exp) const
{
// assert(exp>=0);
ModInt res = 1;
ModInt base = *this;
while (exp)
{
if (exp & 1)
res *= base;
base *= base;
exp >>= 1;
}
return res;
}
ModInt inv() const
{
// assert(v);
return pow(P - 2);
}
friend ModInt operator+(const ModInt &lhs, const ModInt &rhs)
{
ModInt res = lhs;
res += rhs;
return res;
}
friend ModInt operator-(const ModInt &lhs, const ModInt &rhs)
{
ModInt res = lhs;
res -= rhs;
return res;
}
friend ModInt operator*(const ModInt &lhs, const ModInt &rhs)
{
ModInt res = lhs;
res *= rhs;
return res;
}
friend ModInt operator/(const ModInt &lhs, const ModInt &rhs)
{
ModInt res = lhs;
res /= rhs;
return res;
}
friend bool operator==(const ModInt &lhs, const ModInt &rhs) { return lhs.v == rhs.v; }
friend bool operator!=(const ModInt &lhs, const ModInt &rhs) { return lhs.v != rhs.v; }
friend std::istream &operator>>(std::istream &is, ModInt &aim)
{
long long tmp;
is >> tmp;
aim = ModInt(tmp);
return is;
}
friend std::ostream &operator<<(std::ostream &os, const ModInt &aim) { return os << aim.val(); }
private:
long long v;
};
using mint = ModInt<MOD>;
mint fact[200005];
mint infact[200005];
void init()
{
infact[0] = fact[0] = 1;
for(int i = 1;i<= 200002 ;i++)
fact[i] = fact[i-1] * i , infact[i] = infact[i-1] / i;
}
mint C(int a,int b)
{
if( a < b || a < 0 || b < 0 ) return 0;
return fact[a] * infact[b] * infact[a-b];
}
void Solve()
{
int n,k;cin >> k >> n;
mint avg_dep = 0;
mint yenum = 1;
mint rem = 0;
mint ans = 0;
while(n--)
{
mint nxtnum = yenum + k-1;
rem += avg_dep;
avg_dep = (avg_dep * (yenum-1)/nxtnum + (k * (avg_dep + 1) / nxtnum));
yenum += k-1;
// ans += avg_dep * yenum;
// cout<<avg_dep<<" "<<yenum<<"\n";
}
// cout<<ans<<"\n";
cout<<avg_dep * yenum + rem;
}
int main()
{
Solve();
}
詳細信息
Test #1:
score: 100
Accepted
time: 0ms
memory: 6740kb
input:
6 2
output:
18
result:
ok 1 number(s): "18"
Test #2:
score: 0
Accepted
time: 0ms
memory: 6680kb
input:
2 6
output:
600000038
result:
ok 1 number(s): "600000038"
Test #3:
score: 0
Accepted
time: 138ms
memory: 6644kb
input:
83 613210
output:
424200026
result:
ok 1 number(s): "424200026"
Test #4:
score: 0
Accepted
time: 1493ms
memory: 6636kb
input:
48 6713156
output:
198541581
result:
ok 1 number(s): "198541581"
Test #5:
score: 0
Accepted
time: 1ms
memory: 6552kb
input:
1 111
output:
6216
result:
ok 1 number(s): "6216"
Test #6:
score: -100
Time Limit Exceeded
input:
28 7304152