We develop efficient algorithms for computing the expansion of a given
symmetric polynomial into Schur functions. This problem frequently ar
ises in applications as the problem of decomposing a given representat
ion of the symmetric (or general linear) group into irreducible consti
tuents. Our algorithms are probabilistic, and run in time which is pol
ynomial in the sizes of the input and output. They can be used to comp
ute Littlewood-Richardson coefficients, Kostka numbers, and irreducibl
e characters of the symmetric group. (C) 1997 Academic Press.