Ranking and unranking left szilard languages

Erkki Mäkinen
1998 International Journal of Computer Mathematics  
We give efficient ranking and unranking algorithms for left Szilard languages of context-free grammars. If O(n 2 ) time and space preprocessing is allowed then each ranking operation is possible in linear time. Unranking takes time O(n log n). These algorithms imply similar algorithms for context-free languages generated by arbitrary unambiguous context-free grammars.
doi:10.1080/00207169808804677 fatcat:2ge7ci6pybca7meo3rbhckgskm