Implementing basic Tabu Search in R without libraries - r

Question

As part of a data analysis course I need to implement a Tabu search, but since I haven't got a background on CS I'm really struggling to come-up with a solution.
I got the following data:
node <- c(381, 178, 366, 153, 240, 251, 397, 181, 144, 202, 332, 186,
262, 419, 282, 279, 272, 302, 216, 186, 394, 265, 323, 204, 274,
305, 230, 212, 224, 326, 205, 338, 199, 353, 272, 364, 154, 288,
368, 139, 436, 431, 229, 357, 212, 437, 234, 247, 360, 297)
I need to select the 5 smallest elements performing the tabu search. The description from the algorithm has been taken from this book https://cs.gmu.edu/~sean/book/metaheuristics/Essentials.pdf
1: l Desired maximum tabu list length
2: n number of tweaks desired to sample the gradient
3: S some initial candidate solution
4: Best S
5: L {} a tabu list of maximum length l . Implemented as first in, first-out queue
6: Enqueue S into L
7: repeat
8: if Length(L) > l then
9: Remove oldest element from L
10: R Tweak(Copy(S))
11: for n
1 times do
12: W Tweak(Copy(S))
13: if W 2/ L and (Quality(W) > Quality(R) or R 2 L) then
14: R W
15: if R 2/ L then
16: S R
17: Enqueue R into L
18: if Quality(S) > Quality(Best) then
19: Best S
20: until Best is the ideal solution or we have run out of time
21: return Best
I got some of the elements but I'm stuck in adding the elements that don't exist in the tabu list when I get a new solution. I'm not sure how to put all the elements together or if my approach is "acceptable" (even if the algorithm is relatively simple).
max_length <- 20 # max tabu length
iterations <- 100
#set initial solution
solution <- c(sample(node,5,replace = FALSE))
best_solution <- solution
# we create the tabu list
tabu_list <- c()
tabu_list <- c(tabu_list,best_solution)
if(length(tabu_list) > max_length){
tabu_list <- tabu_list[-1:-5] # we eliminate the first 5 elements.
}
#create a new solution
new_node_list<- node[!(node %in% tabu_list)]
solution <- c(sample(new_node_list,5,replace = FALSE))
I can check if an item from the solution exist in the tabu list, but I am not sure how I can add those that don't exist to the tabu list.
which(tabu_list==solution)
## How can I add only those elements from solution that are not included in the tabu list?
Anybody could give me a hand on this one?
Many thanks in advance.