The cell probe complexity of dynamic data structures
STOC '89 Proceedings of the twenty-first annual ACM symposium on Theory of computing
Elements of information theory
Elements of information theory
Compression of Low Entropy Strings with Lempel--Ziv Algorithms
SIAM Journal on Computing
An analysis of the Burrows—Wheeler transform
Journal of the ACM (JACM)
High-order entropy-compressed text indexes
SODA '03 Proceedings of the fourteenth annual ACM-SIAM symposium on Discrete algorithms
SWAT '02 Proceedings of the 8th Scandinavian Workshop on Algorithm Theory
Succinct Dynamic Data Structures
WADS '01 Proceedings of the 7th International Workshop on Algorithms and Data Structures
Sorting and Searching on the Word RAM
STACS '98 Proceedings of the 15th Annual Symposium on Theoretical Aspects of Computer Science
Journal of the ACM (JACM)
Squeezing succinct data structures into entropy bounds
SODA '06 Proceedings of the seventeenth annual ACM-SIAM symposium on Discrete algorithm
Note: A simple storage scheme for strings achieving entropy bounds
Theoretical Computer Science
Compressed representations of sequences and full-text indexes
ACM Transactions on Algorithms (TALG)
Dynamic entropy-compressed sequences and full-text indexes
ACM Transactions on Algorithms (TALG)
Rank/select on dynamic compressed sequences and applications
Theoretical Computer Science
Fully-functional succinct trees
SODA '10 Proceedings of the twenty-first annual ACM-SIAM symposium on Discrete Algorithms
Succinct representations of dynamic strings
SPIRE'10 Proceedings of the 17th international conference on String processing and information retrieval
Statistical encoding of succinct data structures
CPM'06 Proceedings of the 17th Annual conference on Combinatorial Pattern Matching
Dynamic compressed strings with random access
ICALP'13 Proceedings of the 40th international conference on Automata, Languages, and Programming - Volume Part I
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We present a new data structure called the Compressed Random Access Memory (CRAM) that can store a dynamic string T of characters, e.g., representing the memory of a computer, in compressed form while achieving asymptotically almost-optimal bounds (in terms of empirical entropy) on the compression ratio. It allows short substrings of T to be decompressed and retrieved efficiently and, significantly, characters at arbitrary positions of T to be modified quickly during execution without decompressing the entire string. This can be regarded as a new type of data compression that can update a compressed file directly. Moreover, at the cost of slightly increasing the time spent per operation, the CRAM can be extended to also support insertions and deletions. Our key observation that the empirical entropy of a string does not change much after a small change to the string, as well as our simple yet efficient method for maintaining an array of variable-length blocks under length modifications, may be useful for many other applications as well.