Please Help in ||Chef and Interesting Subsequences||

Q link:- https://www.codechef.com/problems/CHEFINSQ

Sol link:-https://www.codechef.com/viewsolution/38155517

I think problem is nCr function. May be overflow
You may try this

nCr
void nCr(int n, int r) 
{
    long long p = 1, k = 1; 
    if (n - r < r) 
        r = n - r; 
  
    if (r != 0) { 
        while (r) { 
            p *= n; 
            k *= r; 
            long long m = __gcd(p, k); 
            p /= m; 
            k /= m; 
  
            n--; 
            r--; 
        } 
    } 
  
    else
        p = 1; 
  
    cout << p << endl;
}
1 Like

Sir out of 7 tasks only the 4th task is wrong task of 5th 6th and 7th are correct are you sure it is overflow issue
can you please give me a test case for that ?

if you can give me a test case it will be very helpful

n=40 and k=25
arr[]=1,1,1…

1 Like

Thanks a lot :smiley: