Certainly! Below is a Python function `tcgen` that generates test cases for the provided competitive programming problem.

```python
import random

def tcgen():
    # Setting the constraints
    N = random.randint(1, 200)
    
    A = [random.randint(1, 10**18) for _ in range(N)]
    
    K = random.randint(1, 10**18)
    
    return N, K, A

# Example usage:
N, K, A = tcgen()
print(N)
print(K)
print(" ".join(map(str, A)))
```

### Explanation:
- **N**: This is set to a random integer between 1 and 200 inclusive, which is the constraint for the number of integers written on the blackboard.
- **A**: This is a list of integers where each element is a random integer between 1 and \(10^{18}\), adhering to the constraints for the integers on the blackboard.
- **K**: This is set to a random integer between 1 and \(10^{18}\), following the constraint for the maximum number of operations.

### How to use:
1. Call the `tcgen` function to generate a test case.
2. The function will print:
   - The number of integers \(N\) on the blackboard.
   - The number of operations \(K\).
   - The list \(A\) of \(N\) integers.

You can use the printed values as input for the problem to test your solution or any other use case you need.