Create 1612-check-if-two-expression-trees-are-equivalent.js

Author: everthis

1612-check-if-two-expression-trees-are-equivalent.js

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+/**
+ * Definition for a binary tree node.
+ * function Node(val, left, right) {
+ *     this.val = (val===undefined ? " " : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {Node} root1
+ * @param {Node} root2
+ * @return {boolean}
+ */
+const checkEquivalence = function(root1, root2) {
+  const q = {}
+  const helper = (node) => {
+    if (node == null) return
+    if(node.val !== '+') {
+      if(q[node.val] == null) q[node.val] = 0
+      q[node.val]++      
+    }
+    helper(node.left)
+    helper(node.right)
+  }
+  helper(root1)
+  const h = node => {
+    if(node == null) return
+    if(node.val !== '+') {
+      if(q[node.val] == null) return false
+      q[node.val]--
+      if(q[node.val] <= 0) delete q[node.val]
+    }
+    h(node.left)
+    h(node.right)
+  }
+  h(root2)
+  if(Object.keys(q).length > 0) return false
+  return true
+};