Repository: TheAlgorithms/Java
File: src/main/java/com/thealgorithms/strings/AhoCorasick.java (Java)

Code before:
                char c = patterns[i].charAt(j); // Get the current character

                // Check if the current node has a child for the current character
                if (curr.child.containsKey(c)) {
                    curr = curr.child.get(c); // Update the current node to the child node
                } else {
                    // If no child node exists, create a new one and add it to the current node's children
                    Node nn = new Node();
                    curr.child.put(c, nn);
                    curr = nn; // Update the current node to the new child node
                }
            }
            curr.pattern_ind = i; // Store the index of the pattern in the current leaf node
        }
    }

    // Builds the suffix links and output links in the Aho-Corasick trie
    public void buildSuffixAndOutputLinks() {
        root.suffix_link = root; // Initialize the suffix link of the root to itself
        Queue<Node> q = new LinkedList<>(); // Initialize a queue for BFS traversal

        // Initialize suffix links for child nodes of the root
        for (char rc : root.child.keySet()) {
            q.add(root.child.get(rc)); // Add child node to the queue
            root.child.get(rc).suffix_link = root; // Set suffix link to the root
        }

        while (!q.isEmpty()) {
            Node currentState = q.poll(); // Get the current node for processing

            // Iterate through child nodes of the current node
            for (char cc : currentState.child.keySet()) {
                Node currentChild = currentState.child.get(cc); // Get the child node
                Node parentSuffix = currentState.suffix_link; // Get the parent's suffix link

                // Calculate the suffix link for the child based on parent's suffix link
                while (!parentSuffix.child.containsKey(cc) && parentSuffix != root) {
                    parentSuffix = parentSuffix.suffix_link;
                }

                // Set the calculated suffix link or default to root
                if (parentSuffix.child.containsKey(cc)) {
                    currentChild.suffix_link = parentSuffix.child.get(cc);
                } else {
                    currentChild.suffix_link = root;
                }

                q.add(currentChild); // Add the child node to the queue for further processing
            }

            // Establish output links for nodes to efficiently identify patterns within patterns

Review comment (suggestion):
This could be moved to a separate method (called something like `initializeSuffixLinksForChildNodesOfTheRoot`). In general, a good method name is the best comment. 

Code after:
        }

        public int getPatternInd() {
            return patternInd;
        }

        public void setPatternInd(final int patternInd) {
            this.patternInd = patternInd;
        }
    }

    // Trie Class
    public static class Trie {

        private Node root = null; // Root node of the trie
        private final String[] patterns; // patterns according to which Trie is constructed

        public Trie(final String[] patterns) {
            root = new Node(); // Initialize the root of the trie
            this.patterns = patterns;
            buildTrie();
            buildSuffixAndOutputLinks();
        }

        // builds AhoCorasick Trie
        private void buildTrie() {

            // Loop through each input pattern and building Trie
            for (int i = 0; i < patterns.length; i++) {
                Node curr = root; // Start at the root of the trie for each pattern

                // Loop through each character in the current pattern
                for (int j = 0; j < patterns[i].length(); j++) {
                    char c = patterns[i].charAt(j); // Get the current character

                    // Check if the current node has a child for the current character
                    if (curr.getChild().containsKey(c)) {
                        curr = curr.getChild().get(c); // Update the current node to the child node
                    } else {
                        // If no child node exists, create a new one and add it to the current node's children
                        Node nn = new Node();
                        curr.getChild().put(c, nn);
                        curr = nn; // Update the current node to the new child node
                    }
                }
                curr.setPatternInd(i); // Store the index of the pattern in the current leaf node
            }
        }

        private void initializeSuffixLinksForChildNodesOfTheRoot(Queue<Node> q) {
            for (char rc : root.getChild().keySet()) {