Pathway Detection from Protein Interaction Networks and Gene Expression Data Using Color-Coding Methods and A* Search Algorithms

Algorithm 1

The pseudocode of the color-coding method.

Input: Network G (V,E), K colors

Output: colored network 𝐺^

(1) Sort all nodes v ∈ V by degree (from high degree to low degree) into Set S

(2) for each v∈S

(3)  If Colored(v) = true go to step 2 and search next node;

(4)  assign one color to node v from k colors;

(5)  Colored(v) = true;

(6)  For each 𝑣^∈ neighbor(v) and Colored(𝑣^) = false;

(7)   If degree(𝑣^) = 1 then assign the same color with v;

(8)     else

(9)    assign color node 𝑣^ that have a different color with hub v from other k-l colors;

(10)   Colored(𝑣^) = true;

(11)   End for

(12) End for

(13) Extract articulation points u from network G;

(14) For each node 𝑢^∈u

(15)   check if u has the same color of any neighbor if so change it;

(16) End for

(17) Return colored network 𝐺^