Certainly! Here's a test case generator for the "Non-redundant Drive" problem statement:

```python
import random

def tcgen():
    # Number of cities
    N = random.randint(1, 100000)
    # Gasoline amounts at each city
    g = [random.randint(1, 10000) for _ in range(N)]
    # Connections between cities
    roads = []
    for i in range(1, N):
        a = i + 1
        b = random.randint(1, i)
        d = random.randint(1, 10000)
        roads.append((a, b, d))
    
    return N, g, roads

def format_test_case(N, g, roads):
    result = []
    result.append(f"{N}")
    result.append(" ".join(map(str, g)))
    for a, b, d in roads:
        result.append(f"{a} {b} {d}")
    return "\n".join(result)

# Example usage
N, g, roads = tcgen()
test_case = format_test_case(N, g, roads)
print(test_case)
```

This script generates a test case for the problem, ensuring that the generated cities and roads form a valid tree structure (since `N-1` roads are generated). It then formats the test case to match the expected input format of the problem statement. 

Explanation of the generator:

1. **Number of cities (N)**: A random integer between 1 and 100,000 is chosen.
2. **Gasoline amounts (g)**: For each city, a random integer between 1 and 10,000 is assigned representing the gasoline available at that city's gas station.
3. **Roads**: To ensure the cities form a tree (connected, acyclic graph), each new city `a` (i.e., `i + 1`) connects to any of the previously added cities `b` (i.e., a random city in the range `[1, i]`). The distance `d` between cities `a` and `b` is a random integer between 1 and 10,000.

The **`format_test_case`** function is used to convert the generated test case into the required string format for the problem statement.

Make sure to adjust the ranges if needed and validate the generated test cases to ensure they fit within the problem constraints.