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IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#351750#8339. Rooted TreekarunaAC ✓150ms3676kbC++201.3kb2024-03-12 14:12:222024-03-12 14:12:22

Judging History

你现在查看的是最新测评结果

  • [2024-03-12 14:12:22]
  • 评测
  • 测评结果:AC
  • 用时:150ms
  • 内存:3676kb
  • [2024-03-12 14:12:22]
  • 提交

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