Greedy Algorithm of Convert Integers into Double-Base Chains

In order to improve greedy algorithm so that it could convert integers into Double-Base Chains more efficiently, we introduce tree structure into greedy algorithm by taking advantage of 2-Line Search method.This improvement accelerates the convergence of greedy algorithm.Compared with the greedy algorithm, new algorithm gains more than 8% in the average length of double-base expansions and 2% in the cost of scalar multiplication.