Max output length is 21

[kaustubh285]

The generated numeric string may include scientific notation (e+21), especially when attempting to generate longer strings (e.g., 35 characters). This impacts the final string generation based on the number, leading to unexpected results.

Steps to Reproduce:

1. Instantiate the RandomGenerator class.
2. Use the generate method with a specified length longer than 21 (e.g., 35)

Observe the output which may have length of less than 35