We give efficient algorithms for finding shortest distances in special types of sparse network where the networks are composed of series of subnetworks which form circles. The algorithms presented in this paper are so called extensions of the non-circular sparse network algorithms The suggested algorithm is composed of two approach parts for only donut shaped sparse network, the one is the node elimination approach and the other the arc elimination approach, Our algorithms for finding all shortest distances can be extended in general circular sparse networks.

Abstract 
1. Introduction 
2. Decomposition algorithms for finding all shortest distances in donut shaped sparse networks 
3. Conclusion 
references

• Kim Jun Hong