function prims(AD)


    n = size(AD)
    n1 = n[1]


    # choose initial vertex from graph
    vertex = 1

    # initialize empty edges array and empty MST
    MST = []
    edges = []
    visited = []
    minEdge = [nothing, nothing, float(Inf)]

    # run prims algorithm until we create an MST
    # that contains every vertex from the graph
    while length(MST) != n1 - 1

        # mark this vertex as visited
        append!(visited, vertex)

        # add each edge to list of potential edges
        for r in 1:n1
            if AD[vertex][r] != 0
                append!(edges, [vertex, r, AD[vertex][r]])
            end
        end
        # find edge with the smallest weight to a vertex
        # that has not yet been visited
        for e in 1:length(edges)
            if edges[e][3] < minEdge[3] && edges[e][2] not in visited
                minEdge = edges[e]
            end
        end
        # remove min weight edge from list of edges
        deleteat!(edges, minEdge)

        # push min edge to MST
        append!(MST, minEdge)

        # start at new vertex and reset min edge
        vertex = minEdge[2]
        minEdge = [nothing, nothing, float(Inf)]
    end

    return MST

end

C = [0 2 3 0 0 0; 2 0 5 3 4 0; 3 5 0 0 4 0; 0 3 0 0 2 3; 0 4 4 2 0 5; 0 0 0 3 5 0]

ERROR: BoundsError
Stacktrace:
 [1] getindex(::Int64, ::Int64) at .number.jl:78
 [2] prims(::Array{Int64,2}) at .untitled-8b8d609f2ac8a0848a18622e46d9d721:70
 [3] top-level scope at none:0

D = [ [0,2,3,0,0,0], [2,0,5,3,4,0], [3,5,0,0,4,0], [0,3,0,0,2,3], [0,4,4,2,0,5], [0,0,0,3,5,0
]]