On the space and time complexity of functions computable by simple programs
We study the space and time complexity of functions computable by simple loop-free programs operating on integers. In particular, we show that any function $f(x_1 , \cdots ,x_k )$ computable by a program using only comparison-based conditional forward branching instructions and the arithmetic operat...
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Published in | SIAM journal on computing Vol. 12; no. 4; pp. 708 - 716 |
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Main Authors | , |
Format | Journal Article |
Language | English |
Published |
Philadelphia, PA
Society for Industrial and Applied Mathematics
01.11.1983
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Subjects | |
Online Access | Get full text |
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Summary: | We study the space and time complexity of functions computable by simple loop-free programs operating on integers. In particular, we show that any function $f(x_1 , \cdots ,x_k )$ computable by a program using only comparison-based conditional forward branching instructions and the arithmetic operations $ + , - $, and truncating division by integer constants (such programs compute exactly the functions definable in Presburger arithmetic) can be computed by an off-line Turing machine in space $s(n)$ and time $n^2 /s(n)$ for any reasonable space bound $s(n)$ between $\log n$ and $n$. Moreover, the space-time trade-off is optimal. |
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ISSN: | 0097-5397 1095-7111 |
DOI: | 10.1137/0212048 |