Certainly! Here's a test case generator for the Quick Sort problem described:

### Test Case Generator for Quick Sort

```python
import random

def generate_card():
    # Generate a random card suit
    suit = random.choice(['S', 'H', 'C', 'D'])
    # Generate a random card number
    number = random.randint(1, 10**9)
    return suit, number

def tcgen(num_cases=1):
    test_cases = []
    
    for _ in range(num_cases):
        # Generate a random number of cards
        n = random.randint(1, 100000)
        cards = set()
        
        while len(cards) < n:
            card = generate_card()
            cards.add(card)
        
        test_case = [f"{n}"]
        for suit, number in cards:
            test_case.append(f"{suit} {number}")
        
        test_cases.append("\n".join(test_case))
    
    return test_cases

# Usage example
if __name__ == "__main__":
    num_cases = 2  # Number of test cases to generate
    cases = tcgen(num_cases)
    for i, case in enumerate(cases):
        print(f"Test Case {i + 1}:\n{case}\n")
```

### Explanation

1. **generate_card()**: This function generates a random card by selecting a random suit from `['S', 'H', 'C', 'D']` and a random number between `1` and `10^9`.

2. **tcgen(num_cases=1)**: This function generates the specified number of test cases (`num_cases`). For each test case:
    - It generates a random number `n` of cards.
    - It uses a set to ensure that there are no identical cards in the input, as per the problem constraints.
    - It constructs the test case in the required format.

### Usage

You can specify the number of test cases you want to generate using the `num_cases` parameter when calling the `tcgen` function. The generated test cases are printed in the specified format.

### Example Output

```
Test Case 1:
6
S 123456789
H 987654321
C 12345678
D 87654321
H 23456789
S 8765432

Test Case 2:
3
S 7654321
D 56789012
C 67890123
```

This generated output can be used for testing your quicksort implementation. Each test case is printed separately, and each card is represented by a suit and a number, ensuring that there are no duplicate cards.