Hi Carlos! This news article from Quanta magazine discusses the problem and contains links to articles with the algorithms you need: https://www.quantamagazine.org/finally-a-fast-algorithm-for-shortest-paths-on-negative-graphs-20230118/

function BellmanFord(graph, source):

distance[source] = 0

// Initialization

for each vertex v in graph:

if v ≠ source:

distance[v] = ∞

predecessor[v] = undefined

// Relaxation

repeat (V-1) times:

for each edge (u, v) in graph:

if distance[u] + weight(u, v) < distance[v]:

distance[v] = distance[u] + weight(u, v)

predecessor[v] = u

// Negative cycle detection (optional)

for each edge (u, v) in graph:

if distance[u] + weight(u, v) < distance[v]:

// Negative cycle found

return (distance, predecessor)