Ref: 2 step by step diagrams added.

analysis/04-reverse-linked-list/diagrams/05_final_state.puml

@@ -0,0 +1,35 @@
+@startuml
+title Step 5 — Final State
+
+object "Node 1" as n1 {
+  value = 1
+}
+
+object "Node 2" as n2 {
+  value = 2
+}
+
+object "Node 3" as n3 {
+  value = 3
+}
+
+n3 --> n2 : next
+n2 --> n1 : next
+n1 --> "null" : next
+
+object "head" as head
+object "previous" as prev
+object "current" as cur
+
+head --> n3
+prev --> n3
+cur --> "null"
+
+note right of head
+When current becomes null,
+previous points to the new head.
+
+head = previous
+end note
+
+@enduml