Let G=(V,E) be an undirected graph, and let s and t be distinct vertices of G. Each edge in G is assigned one of two colors, red or blue.

(a) Design an algorithm that determines if there is a path from s to t with edges of only one color (that is, a path containing either red edges only or blue edges only).

(b) Design an algorithm that determines if there is a path from s to t such that all red edges appear before all blue edges in the path.