The subset product problem asks whether, for given positive integers and a target positive integer
, there is a subset
such that
It is the multiplicative analog of the given-sum version of the subset sum problem. The decision problem is NP-complete,
even though a dynamic programming algorithm
runs in pseudopolynomial time in the numerical
value of .
The reduction from the exact cover problem restricted to 3-sets establishing NP-completeness is credited to Andrew C. Yao in a 1978 private communication (Garey and Johnson 1979, pp. 224 and 325).