QOJ.ac

QOJ

IDProblemSubmitterResultTimeMemoryLanguageFile sizeSubmit timeJudge time
#631100#8339. Rooted TreeMOQEEAC ✓1145ms3712kbC++201.3kb2024-10-11 22:00:482024-10-11 22:00:48

Judging History

你现在查看的是最新测评结果

  • [2024-10-11 22:00:48]
  • 评测
  • 测评结果:AC
  • 用时:1145ms
  • 内存:3712kb
  • [2024-10-11 22:00:48]
  • 提交

answer

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC optimize("O3")
#pragma GCC optimize("O2")
using namespace std;
#define int long long
#define ll long long
#define llu unsigned long long
#define endl "\n"

typedef pair<int, int> PII;

int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};
const long long inf = 1LL << 60;
const int mod = 1e9 + 9;
const int N = 1e7 + 10;
//f[i][j] 表示第i次操作深度为j的点的期望个数

int ksm(int a, int b) 
{
    a = a % mod; 
    int res = 1;
    while (b) {
        if (b & 1) res = res * a % mod;
        a = a * a % mod;
        b >>= 1;
    }
    return res;
}

int inv(int x) 
{
    return ksm(x, mod - 2);
}

void solve()
{
    int n, k;
    cin >> n >> k;
    long long ans = 0;
    long long v = 0;
    long long sum = 1;

    for (int i = 1; i <= k; i++) {
        ans += (v + 1) * n;
        ans %= mod;
        v = ((v + 1) * n + (sum - 1) * v) % mod * inv((sum + n - 1));
        v %= mod;
        sum = sum - 1 + n;
        sum %= mod;
    }
    
    cout << ans << endl;
}

signed main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout << fixed << setprecision(20);
    int T = 1;
    // cin >> T;
    while (T--)
        solve();
    return 0;
}

Details

Tip: Click on the bar to expand more detailed information

Test #1:

score: 100
Accepted
time: 0ms
memory: 3632kb

input:

6 2

output:

18

result:

ok 1 number(s): "18"

Test #2:

score: 0
Accepted
time: 0ms
memory: 3672kb

input:

2 6

output:

600000038

result:

ok 1 number(s): "600000038"

Test #3:

score: 0
Accepted
time: 71ms
memory: 3708kb

input:

83 613210

output:

424200026

result:

ok 1 number(s): "424200026"

Test #4:

score: 0
Accepted
time: 770ms
memory: 3664kb

input:

48 6713156

output:

198541581

result:

ok 1 number(s): "198541581"

Test #5:

score: 0
Accepted
time: 0ms
memory: 3704kb

input:

1 111

output:

6216

result:

ok 1 number(s): "6216"

Test #6:

score: 0
Accepted
time: 837ms
memory: 3652kb

input:

28 7304152

output:

457266679

result:

ok 1 number(s): "457266679"

Test #7:

score: 0
Accepted
time: 470ms
memory: 3676kb

input:

38 4101162

output:

232117382

result:

ok 1 number(s): "232117382"

Test #8:

score: 0
Accepted
time: 1136ms
memory: 3708kb

input:

51 9921154

output:

340670552

result:

ok 1 number(s): "340670552"

Test #9:

score: 0
Accepted
time: 207ms
memory: 3644kb

input:

79 1801157

output:

620550406

result:

ok 1 number(s): "620550406"

Test #10:

score: 0
Accepted
time: 620ms
memory: 3712kb

input:

22 5417157

output:

457449071

result:

ok 1 number(s): "457449071"

Test #11:

score: 0
Accepted
time: 364ms
memory: 3592kb

input:

25 3210162

output:

36368303

result:

ok 1 number(s): "36368303"

Test #12:

score: 0
Accepted
time: 334ms
memory: 3656kb

input:

67 2919160

output:

935195555

result:

ok 1 number(s): "935195555"

Test #13:

score: 0
Accepted
time: 985ms
memory: 3668kb

input:

77 8613163

output:

482832472

result:

ok 1 number(s): "482832472"

Test #14:

score: 0
Accepted
time: 1140ms
memory: 3652kb

input:

90 10000000

output:

275581651

result:

ok 1 number(s): "275581651"

Test #15:

score: 0
Accepted
time: 1138ms
memory: 3708kb

input:

99 9999999

output:

126087169

result:

ok 1 number(s): "126087169"

Test #16:

score: 0
Accepted
time: 1145ms
memory: 3584kb

input:

100 10000000

output:

451590067

result:

ok 1 number(s): "451590067"

Extra Test:

score: 0
Extra Test Passed