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QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#515634 | #8339. Rooted Tree | yaoy | TL | 1156ms | 110632kb | C++20 | 1.3kb | 2024-08-11 19:53:45 | 2024-08-11 19:53:46 |
Judging History
answer
#include <bits/stdc++.h>
using i64 = long long;
constexpr int P = 1E9 + 9;
constexpr int N = 1E7 + 1;
int pre[N], inv[N], E[N];
int norm(int x) {
if (x >= P) {
x -= P;
} else if (x < 0) {
x += P;
}
return x;
}
int power(int x, int exp) {
int ans = 1;
x = norm(x);
while (exp > 0) {
if (exp % 2) {
ans = 1LL * ans * x % P;
}
x = 1LL * x * x % P;
exp /= 2;
}
return ans;
}
int main() {
std::ios::sync_with_stdio(false);
std::cin.tie(nullptr);
int M, K;
std::cin >> M >> K;
inv[0] = pre[0] = 1;
for (int i = 1; i < N; i++) {
pre[i] = 1LL * pre[i - 1] * ((M - 1LL) * i % P + 1) % P;
}
int suf = power(pre[N - 1], P - 2);
for (int i = N - 1; i >= 1; i--) {
inv[i] = 1LL * suf * pre[i - 1] % P;
suf = 1LL * suf * ((M - 1LL) * i % P + 1) % P;
}
int ans = 0;
E[0] = 0;
for (int i = 1; i <= K; i++) {
assert(inv[i - 1] == power((M - 1LL) * (i - 1) % P + 1, P - 2));
int E_dep = 1LL * E[i - 1] * inv[i - 1] % P;
ans = norm(ans + (E_dep + 1LL) * M % P);
E[i] = norm(norm(E[i - 1] + E_dep * (M - 1LL) % P) + M);
}
std::cout << ans << "\n";
return 0;
}
Details
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Test #1:
score: 100
Accepted
time: 96ms
memory: 83696kb
input:
6 2
output:
18
result:
ok 1 number(s): "18"
Test #2:
score: 0
Accepted
time: 100ms
memory: 82496kb
input:
2 6
output:
600000038
result:
ok 1 number(s): "600000038"
Test #3:
score: 0
Accepted
time: 177ms
memory: 85992kb
input:
83 613210
output:
424200026
result:
ok 1 number(s): "424200026"
Test #4:
score: 0
Accepted
time: 1067ms
memory: 110632kb
input:
48 6713156
output:
198541581
result:
ok 1 number(s): "198541581"
Test #5:
score: 0
Accepted
time: 96ms
memory: 83212kb
input:
1 111
output:
6216
result:
ok 1 number(s): "6216"
Test #6:
score: 0
Accepted
time: 1156ms
memory: 110504kb
input:
28 7304152
output:
457266679
result:
ok 1 number(s): "457266679"
Test #7:
score: 0
Accepted
time: 677ms
memory: 100316kb
input:
38 4101162
output:
232117382
result:
ok 1 number(s): "232117382"
Test #8:
score: -100
Time Limit Exceeded
input:
51 9921154
output:
340670552