Improve JS example for tree traversals

Author: zsparal

chapters/tree_traversal/code/javascript/Tree_example.js

@@ -0,0 +1,57 @@
+function createTree(rows, children) {
+ if (rows === 0) {
+ return { id: rows, children: [] };
+ }
+
+ return {
+ id: rows,
+ children: Array.from(Array(children).keys(), () => createTree(rows - 1, children))
+ };
+}
+
+function dfsPreorder(tree) {
+ console.log(tree.id);
+ tree.children.forEach(dfs);
+}
+
+function dfsPostorder(tree) {
+ tree.children.forEach(dfs);
+ console.log(tree.id);
+}
+
+function dfsInorder(tree) {
+ if (!tree) {
+ return;
+ }
+
+ if (tree.children.length > 2) {
+ throw new Error("Postorder traversal is only valid for binary trees");
+ }
+
+ dfsInorder(tree.children[0]);
+ console.log(tree.id);
+ dfsInorder(tree.children[1]);
+}
+
+function dfsIterative(tree) {
+ const stack = [tree];
+ while (stack.length > 0) {
+ const current = stack.pop();
+ console.log(current.id);
+ stack.push(...current.children);
+ }
+}
+
+function bfs(tree) {
+ const queue = [tree];
+ while (queue.length > 0) {
+ const [current] = queue.splice(0, 1);
+ console.log(current.id);
+ queue.push(...current.children);
+ }
+}
+
+const root = createTree(3, 3);
+dfsRecursive(root);
+dfsIterative(root);
+bfs(root);

chapters/tree_traversal/code/javascript/tree.js

@@ -39,7 +39,7 @@ Because of this, the most straightforward way to traverse the tree might be recu
 {% sample lang="c" %}
 [import:37-45, lang:"c_cpp"](code/c/tree_traversal.c)
 {% sample lang="js" %}
-[import:15-23, lang:"javascript"](code/javascript/Tree_example.js)
+[import:12-15, lang:"javascript"](code/javascript/tree.js)
 {% sample lang="py2" %}
 [import:8-16, lang:"python"](code/python2/Tree_example.py)
 {% sample lang="py3" %}
@@ -76,8 +76,7 @@ This has not been implemented in your chosen language, so here is the Julia code
 {% sample lang="c" %}
 [import:47-53, lang:"c_cpp"](code/c/tree_traversal.c)
 {% sample lang="js" %}
-This has not been implemented in your chosen language, so here is the Julia code
-[import:18-26, lang:"julia"](code/julia/Tree.jl)
+[import:17-20, lang:"javascript"](code/javascript/tree.js)
 {% sample lang="py2" %}
 This has not been implemented in your chosen language, so here is the Julia code
 [import:18-26, lang:"julia"](code/julia/Tree.jl)
@@ -111,8 +110,7 @@ This has not been implemented in your chosen language, so here is the Julia code
 {% sample lang="c" %}
 [import:55-73, lang:"c_cpp"](code/c/tree_traversal.c)
 {% sample lang="js" %}
-This has not been implemented in your chosen language, so here is the Julia code
-[import:28-43, lang:"julia"](code/julia/Tree.jl)
+[import:22-34, lang:"javascript"](code/javascript/tree.js)
 {% sample lang="py2" %}
 This has not been implemented in your chosen language, so here is the Julia code
 [import:28-43, lang:"julia"](code/julia/Tree.jl)
@@ -155,7 +153,7 @@ In code, it looks like this:
 {% sample lang="c" %}
 [import:75-93, lang:"c_cpp"](code/c/tree_traversal.c)
 {% sample lang="js" %}
-[import:25-40, lang:"javascript"](code/javascript/Tree_example.js)
+[import:36-43, lang:"javascript"](code/javascript/tree.js)
 {% sample lang="py2" %}
 [import:25-36, lang:"python"](code/python2/Tree_example.py)
 {% sample lang="py3" %}
@@ -188,7 +186,7 @@ And this is exactly what Breadth-First Search (BFS) does! On top of that, it can
 {% sample lang="c" %}
 [import:95-113, lang:"c_cpp"](code/c/tree_traversal.c)
 {% sample lang="js" %}
-[import:42-57, lang:"javascript"](code/javascript/Tree_example.js)
+[import:45-52, lang:"javascript"](code/javascript/tree.js)
 {% sample lang="py2" %}
 [import:38-49, lang:"python"](code/python2/Tree_example.py)
 {% sample lang="py3" %}
@@ -224,7 +222,7 @@ tree_traversal.c
 [import, lang:"c_cpp"](code/c/tree_traversal.c)
 {% sample lang="js" %}
 ### JavaScript
-[import, lang:"javascript"](code/javascript/Tree_example.js)
+[import, lang:"javascript"](code/javascript/tree.js)
 {% sample lang="py2" %}
 ### Python 2
 [import, lang:"python"](code/python2/Tree_example.py)