I was doing a question Advertising Agency Your text to link here... where i need to find NcR but if N is very large i had to use modulo of 10^9+7 but for some reason my answer gets wrong on test 6 where n is very big. I think the problem is not using modulo properly but i cant figure it out. 1475E][SUBMISSION:121841381 - Advertising Agency any help is appreciated. In my code n=to and r=bef;

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

//#include <chrono>
//using namespace std::chrono;

long long multi(long long a, long long b, long long mod){
    return (a * b) % mod;
}

long long power(long long a, long long b, long long mod){
    long long powans = 1;

    for(; b > 0; a = multi(a, a, mod), b /= 2) if(b % 2 == 1) powans = multi(powans, a, mod);

    return powans;
}

void fastscan(int &x)
{
    bool neg=false;
    register int c;
    x =0;
    c=getchar();
    if(c=='-')
    {
        neg = true;
        c=getchar();
    }
    for(;(c>47 && c<58);c=getchar())
        x = (x<<1) + (x<<3) +c -48;
    if(neg)
        x *=-1;
}

int gcd(long long int a,long long int b){
    if(a%b==0)
        return b;
    else
        return gcd(b,a%b);
}
long long int fact(long long int to,long long int bef){
    long long sol=1;
    if(to-bef<bef)
        bef=to-bef;
    long long int p=bef;
    long long int n=1,d=1;
    while(p--){
        n=n*to%1000000007;
        d=d*bef%1000000007;
        long long int m=gcd(n,d);
        n=n/m;
        d=d/m;
        n=n%1000000007;
        d=d%1000000007;
        to--;
        bef--;
    }
    return n;
}

void solve(){
    int n,k;
    cin>>n>>k;
    int arr[n];
    for(int i=0;i<n;i++)
        cin>>arr[i];
    sort(arr,arr+n,greater<int>());
    int value=arr[k-1];
    long long int bef=0,to=0;
    for(int i=0;i<n;i++){
        if(arr[i]==value){
            to++;
            if(i<=k-1)
                bef++;
        }
    }
    long long int sol=1;
    sol=fact(to,bef);
    cout<<sol%1000000007<<endl;
}
int main(){

#ifndef ONLINE_JUDGE
    freopen("input.txt","r",stdin);
    freopen("output.txt","w",stdout);
    freopen("error.txt","w",stderr);
#endif
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    //auto start = high_resolution_clock::now();
    int t;
    cin>>t;
    while(t--) {
        solve();
    }
    // auto stop = high_resolution_clock::now();
    // auto duration = duration_cast<microseconds>(stop - start);
    // cout << duration.count() << endl;
    return 0;
}