Pattern printing cpp

I am new to coding

    I am trying to print a pattern,
     ABCDEF
     G$$$$H
     I$$$$J
     K$$$$L
     M$$$$N
     OPQRST  
    for input N=6

my cpp code for the same is
#include <iostream>
using namespace std;
//This function takes the input size for the pattern
void printPattern(int N)
    {
        int i;//variable for outer loop
        int j;//variable for inner loop
        int c=65;
        for(i=1;i<=N;i++)
        {
            for(j=1;j<=N;j++)
            {
                if(i==1||i==N||j==1||j==N)
                {
                    char ch;
                    ch=c;
                    cout<<ch;
                    c++;
                }

               else
               {
                 cout<<"$";
               }


            }
            cout<<"\n";
        }
    }

int main() {
    int T,N;
    cin>>T;
    for(int i=1;i<=T;i++)u
    {
    cin>>N;
    printPattern(N);
    return 0;
    }
}

It is running perfectly fine for any all the inputs i provide manually but on submitting the code it gives unexpected failing of test cases,e.g. for N=5. I tried giving N as 5 and the output is perfectly fine. can anyone point out where's the problem?