Add js solution to lc problem: no.107

tchx626 · tchx626 · commit db9136f98ad0 · 2021-07-17T22:00:35.000+08:00
diff --git a/solution/0100-0199/0107.Binary Tree Level Order Traversal II/README.md b/solution/0100-0199/0107.Binary Tree Level Order Traversal II/README.md
@@ -106,6 +106,50 @@ class Solution {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {number[][]}
+ */
+var levelOrderBottom = function (root) {
+    if (!root) {
+        return [];
+    }
+    let q = [], output = [], levelOutput = [];
+    q.push(root);
+    q.push(null);
+    while (q.length) {
+        let cur = q.shift();
+        levelOutput.push(cur.val);
+        if (cur.left) {
+            q.push(cur.left);
+        }
+        if (cur.right) {
+            q.push(cur.right);
+        }
+        if (!q[0]) {
+            q.shift();
+            output.unshift(levelOutput);
+            levelOutput = [];
+            if (q.length) {
+                q.push(null);
+            }
+        }
+    }
+    return output;
+};
+```
+
 ### **...**
 
 ```
diff --git a/solution/0100-0199/0107.Binary Tree Level Order Traversal II/README_EN.md b/solution/0100-0199/0107.Binary Tree Level Order Traversal II/README_EN.md
@@ -105,6 +105,50 @@ class Solution {
 }
 ```
 
+### **JavaScript**
+
+```js
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {number[][]}
+ */
+var levelOrderBottom = function (root) {
+    if (!root) {
+        return [];
+    }
+    let q = [], output = [], levelOutput = [];
+    q.push(root);
+    q.push(null);
+    while (q.length) {
+        let cur = q.shift();
+        levelOutput.push(cur.val);
+        if (cur.left) {
+            q.push(cur.left);
+        }
+        if (cur.right) {
+            q.push(cur.right);
+        }
+        if (!q[0]) {
+            q.shift();
+            output.unshift(levelOutput);
+            levelOutput = [];
+            if (q.length) {
+                q.push(null);
+            }
+        }
+    }
+    return output;
+};
+```
+
 ### **...**
 
 ```
diff --git a/solution/0100-0199/0107.Binary Tree Level Order Traversal II/Solution.js b/solution/0100-0199/0107.Binary Tree Level Order Traversal II/Solution.js
@@ -0,0 +1,39 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {number[][]}
+ */
+var levelOrderBottom = function (root) {
+    if (!root) {
+        return [];
+    }
+    let q = [], output = [], levelOutput = [];
+    q.push(root);
+    q.push(null);
+    while (q.length) {
+        let cur = q.shift();
+        levelOutput.push(cur.val);
+        if (cur.left) {
+            q.push(cur.left);
+        }
+        if (cur.right) {
+            q.push(cur.right);
+        }
+        if (!q[0]) {
+            q.shift();
+            output.unshift(levelOutput);
+            levelOutput = [];
+            if (q.length) {
+                q.push(null);
+            }
+        }
+    }
+    return output;
+};
