Fast Searching in Packed Strings
نویسنده
چکیده
Given strings P and Q the (exact) string matching problem is to find all positions of substrings in Q matching P . The classical Knuth-Morris-Pratt algorithm [SIAM J. Comput., 1977] solves the string matching problem in linear time which is optimal if we can only read one character at the time. However, most strings are stored in a computer in a packed representation with several characters in a single word, giving us the opportunity to read multiple characters simultaneously. In this paper we study the worstcase complexity of string matching on strings given in packed representation. Let m ≤ n be the lengths P and Q, respectively, and let σ denote the size of the alphabet. On a standard unit-cost word-RAM with logarithmic word size we present an algorithm using time
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