**Triangle Inequality**

c(u,w) c(u,v) + c(v,w)

(generally satisfied)

An approximation algorithm with ratio bound p = 2 exists for TSPs exhibiting triangle inequality.

Approx-TSP-Tour(G, c)
; G = (V, E), c = edge costs

select root vertex r in V

T = MST-Prim(G, c, r)

L = list of vertices in preorder traversal of T

return cycle with vertices ordered as in L