Time: 235 ms (70.37%), Space: 40.7 MB (40.74%) - LeetHub

Author: hajin-kim

0501-find-mode-in-binary-search-tree/0501-find-mode-in-binary-search-tree.kt

@@ -0,0 +1,20 @@
+class Solution {
+    private val counter = mutableMapOf<Int, Int>()
+
+    private fun TreeNode?.count() {
+        if (this == null)
+            return
+        counter[this.`val`] = (counter[this.`val`] ?: 0) + 1
+        left.count()
+        right.count()
+    }
+
+    fun findMode(root: TreeNode?): IntArray {
+        root.count()
+        val max = counter.values.max()
+        return counter
+            .filter { (_, v) -> v == max }
+            .keys
+            .toIntArray()
+    }
+}