Why am I not getting any output?

In the program I have taken T as the number of test cases.
I am learning precomputation in which I have precomputed all the product of the digits of the numbers and their sizes from 0–>n in two different vectors.
The first line of input is n.
The code is not giving any output sadly, please help me out!
Also it would be great if you could suggest me a better alternative which would have a faster Time Complexity (Want to make it lesser than 1 second)

using namespace std;
const int N=10;
const long long M=1e7;
int main()
vector<long long> product;
vector<long long> size;
for(int i=0;i<M;i++)
    int pl=1,count=0;
    int num=i;
    while(num != 0)
        pl = pl * (num % 10);
        num = num / 10;
int t;
    long long n;
    for(int i=0;i<=n;i++)
        cout<<size[i]<<" "<<product[i]<<endl;
return 0;
} ```

bro u are doing a huge mistake in your Code.initially the size of vector is empty and you are changing their values.it will give Run Time Erro.Give Your vectors some size initially.

vector<long long> product(M);
vector<long long> size(M);

i have idea for better solution.if u are finding the product of digits of a number like 123456.
you are doing logn operations,you can do that in O(1) time.like-
find the product of 12345 in product array and multiply with 6 after that,and same will work for size as well.

Can you please show me the code? I could’nt get you