CSES - Datatähti 2025 alku - Results
Submission details
Task:Kortit II
Sender:adex720
Submission time:2024-11-02 23:16:15 +0200
Language:C++ (C++20)
Status:READY
Result:34
Feedback
groupverdictscore
#1ACCEPTED3
#2ACCEPTED5
#3ACCEPTED26
#40
#50
Test results
testverdicttimegroup
#1ACCEPTED0.00 s1, 2, 3, 4, 5details
#2ACCEPTED0.00 s2, 3, 4, 5details
#3ACCEPTED0.72 s3, 4, 5details
#4--4, 5details
#5--5details
#6--5details

Compiler report

input/code.cpp: In function 'long long int binomikerroin(int, int)':
input/code.cpp:15:9: warning: unused variable 'a' [-Wunused-variable]
   15 |     int a = n * 1002 + k;
      |         ^

Code

#include <bits/stdc++.h>
using namespace std;

int mod = 1e9 + 7;

unordered_map<int, int> muistiBinomi;
long long binomikerroin(int n, int k)
{
    if (k > (n >> 1))
        return binomikerroin(n, n - k);

    if (k == 0)
        return 1LL;

    int a = n * 1002 + k;

    return (binomikerroin(n - 1, k - 1) + binomikerroin(n - 1, k)) % mod;
}

unordered_map<int, int> muisti;

long long laske(int n, int r)
{
    if (n == 0)
        return 0;
    if (n == r + 1 || r == 1)
        return 1;

    // r * laske(n - 1, r) + (n - r) * laske(n - 1, r - 1) + (n - 1) * laske(n - 2, r - 1)
    return ((r * laske(n - 1, r)) % mod + ((n - r) * laske(n - 1, r - 1)) % mod + ((n - 1) * laske(n - 2, r - 1)) % mod) % mod;
}

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr);

    int t, n, a, b;
    cin >> t;

    int kertomat[2001];
    kertomat[1] = 1;

    for (long long i = 2; i <= 2000; i++)
    {
        kertomat[i] = (kertomat[i - 1] * i) % mod;
    }

    /*for (int y = 0; y < 10; y++)
    {
        for (int x = 0; x <= y; x++)
        {
            cout << binomikerroin(y, x) << " ";
        }
        cout << "\n";
    }*/

    for (int i = 0; i < t; i++)
    {
        cin >> n >> a >> b;
        int voittoja = a + b;

        if (voittoja < 0 || voittoja > n || ((a == 0) ^ (b == 0)))
        {
            cout << "0\n";
            continue;
        }

        if (a == 0 && b == 0)
        {
            cout << kertomat[n] << "\n";
            continue;
        }

        int tasapeleja = binomikerroin(n, n - voittoja);

        long long ereja = laske(voittoja, min(a, b));

        cout << (((ereja * tasapeleja) % mod) * kertomat[n]) % mod << "\n";
    }
}

Test details

Test 1

Group: 1, 2, 3, 4, 5

Verdict: ACCEPTED

input
54
4 4 0
3 1 3
3 2 2
4 0 4
...

correct output
0
0
0
0
0
...

user output
0
0
0
0
0
...

Test 2

Group: 2, 3, 4, 5

Verdict: ACCEPTED

input
284
6 1 0
5 0 2
7 1 5
7 7 5
...

correct output
0
0
35280
0
36720
...

user output
0
0
35280
0
36720
...

Test 3

Group: 3, 4, 5

Verdict: ACCEPTED

input
841
19 3 12
19 19 13
19 7 13
20 11 15
...

correct output
40291066
0
0
0
0
...

user output
40291066
0
0
0
0
...

Test 4

Group: 4, 5

Verdict:

input
1000
15 12 6
7 1 6
44 4 26
6 6 5
...

correct output
0
5040
494558320
0
340694548
...

user output
(empty)

Test 5

Group: 5

Verdict:

input
1000
892 638 599
966 429 655
1353 576 1140
1403 381 910
...

correct output
0
0
0
249098285
0
...

user output
(empty)

Test 6

Group: 5

Verdict:

input
1000
2000 1107 508
2000 1372 249
2000 588 65
2000 1739 78
...

correct output
750840601
678722180
744501884
159164549
868115056
...

user output
(empty)