Create 1457-pseudo-palindromic-paths-in-a-binary-tree.kt

Author: a93a

kotlin/1457-pseudo-palindromic-paths-in-a-binary-tree.kt

@@ -0,0 +1,27 @@
+class Solution {
+    fun pseudoPalindromicPaths (root: TreeNode?): Int {
+        val count = IntArray (10)
+        var odd = 0
+
+        fun dfs(node: TreeNode?): Int {
+            node ?: return 0
+
+            count[node.`val`]++
+            val oddChange = if (count[node.`val`] % 2 == 1) 1 else -1
+            odd += oddChange
+
+            var res = 0
+            if (node.left == null && node.right == null)
+                res = if (odd <= 1) 1 else 0
+            else
+                res = dfs(node.left) + dfs(node.right)
+
+            odd -= oddChange
+            count[node.`val`]--
+
+            return res
+        }
+
+        return dfs(root)
+    }
+}