Table 11 Performance of the improved exact algorithm by decreasing space complexity

Number of all solutions (N)

541

4683

47,293

545,835

7,087,261

Left solutions \(\left(\sum\limits_{q = 1}^{Q} {S_{q} }\right)\)

49

133

249

599

1142

Solutions cut off

492

4550

47,044

545,236

7,086,119

Ratio of solutions cut off (%)

91

97

99.5

99.9

99.98

Time of enumeration based-NS (second)

0.06

1.4

–

–

–

Total time of the improved algorithm (second)

0.03

0.27

2.24

25.9

342