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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#351749 | #8339. Rooted Tree | karuna | WA | 100ms | 3636kb | C++20 | 1.2kb | 2024-03-12 14:11:27 | 2024-03-12 14:11:29 |
Judging History
answer
#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int MOD = 1e9 + 9;
struct mint {
int x;
mint() : x(0) {}
mint(int x) : x(x) {}
mint operator+(int ot) const { return x + ot >= MOD ? x + ot - MOD : x + ot; }
mint operator-(int ot) const { return x < ot ? x - ot + MOD : x - ot; }
mint operator*(int ot) const { return 1ll * x * ot % MOD; }
mint operator+=(int ot) { return *this = *this + ot; }
mint operator-=(int ot) { return *this = *this - ot; }
mint operator*=(int ot) { return *this = *this * ot; }
operator int() { return x; }
};
mint mpow(mint a, ll x) {
mint r = 1;
while (x) {
if (x & 1) r *= a;
a *= a;
x /= 2;
}
return r;
}
int main() {
cin.tie(0); ios_base::sync_with_stdio(0);
int m, k;
cin >> m >> k;
mint a = 0, b = 0, c = 1;
for (int i = 0; i < k; i++) {
c *= (m - 1) * i + 1;
}
c = mpow(c, MOD - 2);
a = 1 + mpow(m - 1, MOD - 2);
b = mint(0) - mpow((m - 1) * (m - 1), MOD - 2) * m;
a *= c;
b *= c;
for (int s = 1; s <= k; s++) {
mint c = a * (k - s) * (m - 1) + a * m;
mint d = b * (k - s) * (m - 1) + (a + b) * m;
a = c; b = d;
}
b += mpow((m - 1) * (m - 1), MOD - 2) * m;
cout << b << '\n';
}
Details
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Test #1:
score: 100
Accepted
time: 0ms
memory: 3636kb
input:
6 2
output:
18
result:
ok 1 number(s): "18"
Test #2:
score: 0
Accepted
time: 0ms
memory: 3604kb
input:
2 6
output:
600000038
result:
ok 1 number(s): "600000038"
Test #3:
score: 0
Accepted
time: 10ms
memory: 3560kb
input:
83 613210
output:
424200026
result:
ok 1 number(s): "424200026"
Test #4:
score: 0
Accepted
time: 100ms
memory: 3556kb
input:
48 6713156
output:
198541581
result:
ok 1 number(s): "198541581"
Test #5:
score: -100
Wrong Answer
time: 0ms
memory: 3556kb
input:
1 111
output:
111
result:
wrong answer 1st numbers differ - expected: '6216', found: '111'