Runtime: 94 ms (Top 5.29%) | Memory: 74.9 MB (Top 5.05%)

Author: AnasImloul

scripts/algorithms/L/Lexicographical Numbers/Lexicographical Numbers.java

@@ -0,0 +1,54 @@
+// Runtime: 94 ms (Top 5.29%) | Memory: 74.9 MB (Top 5.05%)
+class Solution {
+
+    private final TrieNode trie = new TrieNode(' ');
+
+    class TrieNode{
+
+        private Character digit;
+        private String value;
+        private boolean isWord;
+        private Map<Character, TrieNode> children;
+
+        TrieNode(Character c){
+            this.digit = c;
+            this.isWord = false;
+            this.children = new HashMap<>();
+        }
+
+        void insert(String s){
+            TrieNode current = this;
+            for(Character c : s.toCharArray()){
+                current = current.children.computeIfAbsent(c, k -> new TrieNode(c));
+            }
+            current.value = s;
+            current.isWord = true;
+        }
+
+        List<Integer> getWordsPreOrder(){
+            return getWordsPreOrder(this);
+        }
+
+        private List<Integer> getWordsPreOrder(TrieNode root){
+            List<Integer> result = new ArrayList<>();
+            if(root == null){
+                return result;
+            }
+
+            if(root.isWord){
+                result.add(Integer.parseInt(root.value));
+            }
+            for(TrieNode node : root.children.values()){
+                result.addAll(getWordsPreOrder(node));
+            }
+            return result;
+        }
+    }
+
+    public List<Integer> lexicalOrder(int n) {
+        for(int i = 1 ; i<=n;i++){
+            trie.insert(String.valueOf(i));
+        }
+        return trie.getWordsPreOrder();
+    }
+}