inverse suffix array

(data structure)

Definition: For each position in a string, the inverse suffix array has its index in the string's suffix array.

Formal Definition: Given a suffix array, sa, and the corresponding inverse suffix array, isa, isa[i] = j iff sa[j] = i.

Generalization (I am a kind of ...)

See also suffix array.

Note: Consider the string "good". In 1-based indexing, the suffix array is [4, 1, 3, 2]. The inverse suffix array is [2, 4, 3, 1].

Many algorithms to build suffix arrays use an inverse suffix array. A suffix array can be built from the inverse suffix array in linear time. An inverse suffix array can be turned into a suffix array in place in linear time, too.

Author: PEB

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Entry modified 16 November 2016.
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Cite this as:
Paul E. Black, "inverse suffix array", in Dictionary of Algorithms and Data Structures [online], Vreda Pieterse and Paul E. Black, eds. 16 November 2016. (accessed TODAY) Available from: