Trie JS

// JavaScript program to sort an array of strings
// using Trie

const MAX_CHAR = 26;

class Trie {

    // index is set when node is a leaf
    // node, otherwise -1;
    /*to make new trie*/
    constructor()
    {
        this.child = new Array(MAX_CHAR).fill(null);
        this.index = -1;
    }
}

/* function to insert in trie */
function insert(root,str,index)
{
    let node = root;

    for (let i = 0; i < str.length; i++) {

        /* taking ascii value to find index of
        child node */
        let ind = str.charCodeAt(i) - 'a'.charCodeAt(0);

        /* making new path if not already */
        if (node.child[ind] == null)
            node.child[ind] = new Trie();

        // go to next node
        node = node.child[ind];
    }

    // Mark leaf (end of word) and store
    // index of word in arr[]
    node.index = index;
}

/* function for preorder traversal */
function preorder(node, arr)
{
    if (node == null)
        return false;

    for (let i = 0; i < MAX_CHAR; i++) {
        if (node.child[i] != null) {

            /* if leaf node then print key*/
            if (node.child[i].index != -1)
                document.write(arr[node.child[i].index],"</br>");

            preorder(node.child[i], arr);
        }
    }
}

function printSorted(arr,n)
{
    let root = new Trie();

    // insert all keys of dictionary into trie
    for (let i = 0; i < n; i++)
        insert(root, arr[i], i);

    // print keys in lexicographic order
    preorder(root, arr);
}

// Driver code

let arr = [ "abc", "xy", "bcd" ];
let n = arr.length;
printSorted(arr, n);

// This code is contributed by shinjanpatra