Remove dependency on Combinatorics package.

Project.toml

@@ -2,10 +2,9 @@ name = "SecretSanta"
 uuid = "bb3d3a65-b032-5cdd-a073-dfed7b606c01"
 authors = ["Byron Tasseff"]
 repo = "https://github.com/tasseff/SecretSanta.jl"
-version = "0.2.2"
+version = "0.2.3"
 
 [deps]
-Combinatorics = "861a8166-3701-5b0c-9a16-15d98fcdc6aa"
 Dates = "ade2ca70-3891-5945-98fb-dc099432e06a"
 HiGHS = "87dc4568-4c63-4d18-b0c0-bb2238e4078b"
 JSON = "682c06a0-de6a-54ab-a142-c8b1cf79cde6"
@@ -14,7 +13,6 @@ Random = "9a3f8284-a2c9-5f02-9a11-845980a1fd5c"
 SMTPClient = "c35d69d1-b747-5018-a192-25bc5e63c83d"
 
 [compat]
-Combinatorics = "~1"
 HiGHS = "~1"
 JSON = "~0.21"
 JuMP = "~0.22, ~0.23, ~1"

src/SecretSanta.jl

@@ -1,6 +1,5 @@
 module SecretSanta
 
-import Combinatorics
 import Dates
 import HiGHS
 import JSON
@@ -27,7 +26,7 @@ function SecretSantaModel(data::Dict{String,Any})
 
     # Create arcs for a complete bipartite graph.
     exclude = vcat([[[x["email"], y] for y in x["exclude"]] for x in P]...)
-    A = collect(Combinatorics.combinations(N, 2)) # Collect arcs from i to j.
+    A = get_combinations(N) # Get arcs from i to j.
     A = vcat([reverse(a) for a in A], A) # Concatenate arcs from j to i.
     A = filter(x -> !(x in exclude), A) # Remove excluded arcs.
     A = [(a[1], a[2]) for a in A] # Convert to array of tuples.
@@ -68,6 +67,19 @@ function build_model(input_path::String)
 end
 
 
+function get_combinations(entries::Vector{String})::Vector{Vector{String}}
+    combinations = Vector{Vector{String}}()
+
+    for i in 1:length(entries)
+        for j in (i + 1):length(entries)
+            push!(combinations, [entries[i], entries[j]])
+        end
+    end
+
+    return combinations
+end
+
+
 function solve_model(ssm::SecretSantaModel)
     JuMP.optimize!(ssm.model)