Table 1. Sample Statistical Results of Transformer-Based and GRU-Based Generators.

	pretrained model		optimized model (aver reward = 15)
	transformer	GRU	transformer	GRU
invalid	1.694% ± 0.102%	4.368% ± 0.361%	1.170% ± 0.052%	2.690% ± 0.167%
redundant	0.075% ± 0.022%	0.038% ± 0.015%	30.273% ± 0.525%	33.828% ± 0.616%
retained	98.231% ± 0.115%	95.594% ± 0.351%	68.557% ± 0.552%	63.482% ± 0.456%