Algorithm for finding two-dimensional site percolation backbones

We present an efficient algorithm for finding the current-carrying backbone in the planar site percolation model, It finds the backbone in speed to be almost four times as high as that of the old-fashioned Tarjan's depth-firs t-search algorithm. The scaling exponent (q/v) (beta/v) of the probability that a site belongs to the backbone (the infinite cluster) is found to be 0 .3647 +/- 0.0039 (0.1068 +/- 0.0013) and satisfy Chayes' exponent inequalit y: 2 beta less than or equal to q. (C) 2000 Elsevier Science B.V. All right s reserved.