CSES - Datatähti 2025 alku - Results
Submission details
Task:Tikut
Sender:Chenran
Submission time:2024-11-10 20:48:01 +0200
Language:C++ (C++20)
Status:READY
Result:0
Feedback
groupverdictscore
#10
#20
#30
#40
#50
#60
Test results
testverdicttimegroup
#1ACCEPTED0.00 s1, 3, 4, 5, 6details
#20.00 s1, 4, 5, 6details
#30.00 s1, 4, 5, 6details
#40.00 s1, 4, 5, 6details
#50.01 s2, 5, 6details
#60.01 s2, 5, 6details
#70.03 s3, 5, 6details
#80.01 s3, 5, 6details
#90.01 s3, 5, 6details
#100.01 s3, 5, 6details
#110.01 s3, 5, 6details
#120.01 s4, 5, 6details
#130.00 s4, 5, 6details
#140.00 s4, 5, 6details
#150.00 s4, 5, 6details
#160.00 s5, 6details
#170.01 s5, 6details
#180.00 s5, 6details
#190.01 s5, 6details
#200.19 s6details
#210.06 s6details
#220.19 s6details

Code

#include <iostream>

using namespace std;

const int MAX_N = 2000;
const long long MOD = 1000000007;

long long F[MAX_N + 1]{};
long long A[MAX_N + 1][MAX_N + 1]{};
long long C[MAX_N + 1][MAX_N + 1]{};
long long D[MAX_N + 1][MAX_N + 1]{};

long long compute_factorial(int n)
{
    if (n == 0)
        return 1;

    if (F[n] != 0)
        return F[n];

    F[n] = n * compute_factorial(n - 1) % MOD;

    return F[n];
}

long long compute_eulerian_number(int n, int k)
{
    if (n == k)
        return 0;

    if (A[n][k] != 0)
        return A[n][k];

    if (k >= n - k)
        k = n - k - 1;

    if (k == 0)
        return 1;

    A[n][k] = ((n - k) * compute_eulerian_number(n - 1, k - 1) % MOD +
               (k + 1) * compute_eulerian_number(n - 1, k) % MOD) %
              MOD;
    A[n][n - k - 1] = A[n][k];

    return A[n][k];
}

long long compute_binomial_coefficient(int n, int k)
{
    if (k == 0 || k == n)
        return 1;

    if (C[n][k] != 0)
        return C[n][k];

    if (k > n - k)
        k = n - k;

    C[n][k] = (compute_binomial_coefficient(n - 1, k - 1) +
               compute_binomial_coefficient(n - 1, k)) %
              MOD;
    C[n][n - k] = C[n][k];

    return C[n][k];
}

long long compute_derangement(int n, int k)
{
    if (D[n][k] != 0)
        return D[n][k];

    if (k > n - k)
        k = n - k;

    long long sum = 0;
    for (int j = 0; j < n - k; j++)
    {
        long long binomial = compute_binomial_coefficient(n, j);
        long long eulerian = compute_eulerian_number(n - j, k);
        long long item = binomial * eulerian % MOD;
        item = j % 2 == 0 ? item : MOD - item;
        sum += item;
        sum %= MOD;
    }
    D[n][k] = D[n][n - k] = sum;

    return sum;
}

int main()
{
    int t;
    cin >> t;

    while (t--)
    {
        int n, a, b;
        cin >> n >> a >> b;

        if ((a != 0 && b == 0) || (a == 0 && b != 0) || (a + b > n))
        {
            cout << 0 << endl;
            continue;
        }

        int tie = n - a - b;

        long long n_derangement = compute_derangement(n - tie, b);
        long long n_factorial = compute_factorial(n);
        long long n_tie_binomial = compute_binomial_coefficient(n, tie);
        long long result = n_derangement *
                           n_factorial % MOD *
                           n_tie_binomial % MOD;

        cout << result << endl;
    }

    return 0;
}

Test details

Test 1

Group: 1, 3, 4, 5, 6

Verdict: ACCEPTED

input
1 1
6

correct output

user output
0

Test 2

Group: 1, 4, 5, 6

Verdict:

input
5 10
4 8 6 2 7

correct output
5 4 2 2 2 1 1 1 1 1 

user output
0
0
0
0
0

Test 3

Group: 1, 4, 5, 6

Verdict:

input
5 10
5 5 8 6 7

correct output
3 3 2 3 2 2 1 1 1 2 

user output
714243786
0
0
0
0

Test 4

Group: 1, 4, 5, 6

Verdict:

input
5 10
8 7 9 6 10

correct output
4 4 3 3 2 2 1 2 2 1 

user output
0
0
0
0
0

Test 5

Group: 2, 5, 6

Verdict:

input
1000 1071
3 2 3 1 3 3 2 3 2 3 2 2 2 1 2 ...

correct output
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 ...

user output
675168914
0
0
0
0
...

Test 6

Group: 2, 5, 6

Verdict:

input
1000 1500
3 2 2 3 2 3 2 2 2 3 2 2 3 3 3 ...

correct output
2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 ...

user output
758314082
0
0
0
0
...

Test 7

Group: 3, 5, 6

Verdict:

input
1000 2
15 710 210 347 398 66 318 277 ...

correct output
994 994 

user output
0
0
0
0
0
...

Test 8

Group: 3, 5, 6

Verdict:

input
1000 2
743 890 592 942 736 969 616 50...

correct output
498 496 

user output
0
0
0
0
0
...

Test 9

Group: 3, 5, 6

Verdict:

input
1000 2
987 968 920 994 988 918 914 95...

correct output
500 500 

user output
0
0
0
0
0
...

Test 10

Group: 3, 5, 6

Verdict:

input
1000 2
996 1000 998 998 999 997 997 9...

correct output
500 500 

user output
0
0
0
0
0
...

Test 11

Group: 3, 5, 6

Verdict:

input
1000 2
501 501 501 501 501 501 501 50...

correct output
1 168 

user output
0
0
0
0
0
...

Test 12

Group: 4, 5, 6

Verdict:

input
100 200
145 136 74 83 73 36 196 115 11...

correct output
194 190 189 183 182 181 181 17...

user output
0
0
0
0
0
...

Test 13

Group: 4, 5, 6

Verdict:

input
100 200
157 110 168 155 192 107 146 15...

correct output
95 96 96 95 93 94 94 94 90 91 ...

user output
0
0
0
0
0
...

Test 14

Group: 4, 5, 6

Verdict:

input
50 200
137 118 160 118 146 160 140 18...

correct output
98 98 98 96 90 91 88 88 84 86 ...

user output
0
0
0
0
0
...

Test 15

Group: 4, 5, 6

Verdict:

input
100 200
147 174 186 148 155 128 158 18...

correct output
99 99 98 98 97 97 96 96 95 95 ...

user output
0
0
0
0
0
...

Test 16

Group: 5, 6

Verdict:

input
1000 2000
928772177 816188227 216592201 ...

correct output
991676844 990940224 990685481 ...

user output
0
0

Test 17

Group: 5, 6

Verdict:

input
1000 2000
665759876 597950008 615453266 ...

correct output
498801198 498681904 498504321 ...

user output
0
0
0
0
0
...

Test 18

Group: 5, 6

Verdict:

input
500 2000
683288817 784230412 626685186 ...

correct output
497667621 498434895 495465990 ...

user output
0
0
0
0
0
...

Test 19

Group: 5, 6

Verdict:

input
1000 2000
666667000 809309500 571572000 ...

correct output
499499500 499249250 498999000 ...

user output
0
0
0
0
0
...

Test 20

Group: 6

Verdict:

input
100000 200000
861772559 734298084 983382252 ...

correct output
499973914 499985299 499985141 ...

user output
0
0
0
0
0
...

Test 21

Group: 6

Verdict:

input
30000 200000
691834579 617419813 514778075 ...

correct output
499967533 499976270 499969810 ...

user output
0
0
0
0
0
...

Test 22

Group: 6

Verdict:

input
100000 200000
820255000 960780000 741965000 ...

correct output
499995000 499992500 499990000 ...

user output
0
0
0
0
0
...