leetcode

commit 371f3169daeaba61730f4241254535d9802d9163
parent 18a386dc9d35a170751d6113485da81fcf84a2bb
Author: AndrewLockVI <andrewlaack1@gmail.com>
Date:   Sat, 29 Apr 2023 16:34:41 -0500

Completed BFS search mirrored tree problem using JS

Diffstat:
A
symetric-tree/symetric-tree.js
 | 
69
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

1 file changed, 69 insertions(+), 0 deletions(-)
diff --git a/symetric-tree/symetric-tree.js b/symetric-tree/symetric-tree.js
@@ -0,0 +1,69 @@
+//Go through a binary tree and check if it is symetrical
+//The time complexity of this code is O(n) where n is the number of
+//nodes in the tree. This algorithm uses BFS to search layer by layer and verify
+//that each layer is symetrical from the left and the right.
+
+/**
+ * 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 {boolean}
+ */
+let arr = new Array();
+var isSymmetric = function(root) {
+    let queue = [];
+    queue.push(root);
+    while(queue.length != 0){
+        let queue_len = queue.length;
+        let valid = false;
+        for(let i = 0 ; i < queue_len ; ++i){
+            let current_node = queue.pop();
+            if(current_node != null){
+                if(current_node.left != null){
+                    queue.unshift(current_node.left);
+                    valid = true;
+                }
+                else{
+                    let tree1 = new TreeNode();
+                    tree1.val = -1;
+                    queue.unshift(tree1);
+                }
+                if(current_node.right != null){
+                    queue.unshift(current_node.right);
+                    valid = true;
+                }
+                else{
+                    let tree = new TreeNode();
+                    tree.val = -1;
+                    queue.unshift(tree);
+                }
+            }
+        }
+        if(valid != true){
+            return true;
+        }
+        if(queue.length != -1){
+            if(symetrical(queue) == false){
+                return false;
+            }
+        }
+    }
+    return true;
+};
+let symetrical = (arr) => {
+    if(arr.length%2 != 0){
+        return false;
+    }
+    for(let i = 0 ; i < arr.length / 2 + 1; ++i){
+        if(arr[i].val != arr[arr.length - i - 1].val){
+            return false;
+        }
+    }
+    return true;
+}