Sure, I can help with that! Here's a test case generator for the given problem statement "There is No Alternative":

```python
import random

def tcgen():
    # Number of islands
    N = random.randint(3, 500)
    
    # Number of possible bridges
    M = random.randint(N - 1, min(50000, N * (N - 1) // 2))
    
    bridge_set = set()
    
    # Generate M bridges
    bridges = []
    for _ in range(M):
        while True:
            S = random.randint(1, N - 1)
            D = random.randint(S + 1, N)
            if (S, D) not in bridge_set:
                bridge_set.add((S, D))
                break
        C = random.randint(1, 10000)
        bridges.append((S, D, C))
    
    return N, M, bridges

# Printing a test case example
N, M, bridges = tcgen()
print(N, M)
for bridge in bridges:
    print(bridge[0], bridge[1], bridge[2])
```

This test case generator produces random test cases for the given problem. Here's a breakdown of what it does:

1. **Number of Islands (`N`)**: Picks a random number of islands between 3 and 500.
2. **Number of Possible Bridges (`M`)**: Picks a random number of bridges between `N - 1` and the minimum of 50000 and the maximum possible number of unique bridges for `N` islands.
3. **Bridge Generation**: Ensures that each pair of islands `(S, D)` is unique and generates a random cost `C` for each bridge.
4. **Output**: Prints the number of islands, the number of bridges, and the details of each bridge.

You can run this script to generate different test cases as needed.