QOJ.ac
QOJ
ID | Problem | Submitter | Result | Time | Memory | Language | File size | Submit time | Judge time |
---|---|---|---|---|---|---|---|---|---|
#351750 | #8339. Rooted Tree | karuna | AC ✓ | 150ms | 3676kb | C++20 | 1.3kb | 2024-03-12 14:12:22 | 2024-03-12 14:12:22 |
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;
if (m == 1) {
cout << (ll)k * (k + 1) / 2 % MOD << '\n';
return 0;
}
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
Tip: Click on the bar to expand more detailed information
Test #1:
score: 100
Accepted
time: 1ms
memory: 3620kb
input:
6 2
output:
18
result:
ok 1 number(s): "18"
Test #2:
score: 0
Accepted
time: 0ms
memory: 3620kb
input:
2 6
output:
600000038
result:
ok 1 number(s): "600000038"
Test #3:
score: 0
Accepted
time: 10ms
memory: 3616kb
input:
83 613210
output:
424200026
result:
ok 1 number(s): "424200026"
Test #4:
score: 0
Accepted
time: 100ms
memory: 3572kb
input:
48 6713156
output:
198541581
result:
ok 1 number(s): "198541581"
Test #5:
score: 0
Accepted
time: 0ms
memory: 3676kb
input:
1 111
output:
6216
result:
ok 1 number(s): "6216"
Test #6:
score: 0
Accepted
time: 111ms
memory: 3636kb
input:
28 7304152
output:
457266679
result:
ok 1 number(s): "457266679"
Test #7:
score: 0
Accepted
time: 58ms
memory: 3556kb
input:
38 4101162
output:
232117382
result:
ok 1 number(s): "232117382"
Test #8:
score: 0
Accepted
time: 148ms
memory: 3612kb
input:
51 9921154
output:
340670552
result:
ok 1 number(s): "340670552"
Test #9:
score: 0
Accepted
time: 27ms
memory: 3560kb
input:
79 1801157
output:
620550406
result:
ok 1 number(s): "620550406"
Test #10:
score: 0
Accepted
time: 81ms
memory: 3676kb
input:
22 5417157
output:
457449071
result:
ok 1 number(s): "457449071"
Test #11:
score: 0
Accepted
time: 48ms
memory: 3628kb
input:
25 3210162
output:
36368303
result:
ok 1 number(s): "36368303"
Test #12:
score: 0
Accepted
time: 40ms
memory: 3632kb
input:
67 2919160
output:
935195555
result:
ok 1 number(s): "935195555"
Test #13:
score: 0
Accepted
time: 128ms
memory: 3652kb
input:
77 8613163
output:
482832472
result:
ok 1 number(s): "482832472"
Test #14:
score: 0
Accepted
time: 149ms
memory: 3556kb
input:
90 10000000
output:
275581651
result:
ok 1 number(s): "275581651"
Test #15:
score: 0
Accepted
time: 149ms
memory: 3652kb
input:
99 9999999
output:
126087169
result:
ok 1 number(s): "126087169"
Test #16:
score: 0
Accepted
time: 150ms
memory: 3564kb
input:
100 10000000
output:
451590067
result:
ok 1 number(s): "451590067"
Extra Test:
score: 0
Extra Test Passed