Power indices of weighted majority games are measures of the effects of parties on the voting in a council. Among the many kinds of power indices, Banzhaf index, Shapley-Shubik index and Deegan-Packel index have been studied well. For computing these power indices, dynamic programming algorithms had been proposed. The time complexities of these algorithms are O (n²q), O (n³q), and O (n⁴q), respectively. We propose new algorithms for computing power indices, whose time complexities are O (nq), O (n²q), and O (n²q), respectively.
Takeaki Uno (Fri,) studied this question.