AC https://leetcode-cn.com/problems/maximum-width-of-binary-tree

Author: AaronLinRC

src/main/kotlin/leetcode/maximum-width-of-binary-tree/Solution.kt

@@ -0,0 +1,60 @@
+package leetcode.`maximum-width-of-binary-tree`
+
+import TreeNode
+import org.junit.Test
+import java.util.LinkedList
+import kotlin.math.abs
+
+class Solution {
+    fun widthOfBinaryTree(root: TreeNode?): Int {
+        root ?: return 0
+        val queue = LinkedList<PostionTreeNode>()
+        var currentDep = 0
+        var maxWidth = 1
+        var f: Int? = null
+        queue.push(PostionTreeNode(root, 0, 1))
+        while (queue.isNotEmpty()) {
+            val k = queue.poll() as PostionTreeNode
+            if (currentDep != k.depth) {
+                currentDep = k.depth
+                f = k.postion
+            } else {
+                if (f == null) {
+                    f = k.postion
+                }
+                maxWidth = Math.max(maxWidth, k.postion - f + 1)
+            }
+            if (k.node.left != null) {
+                queue.offer(PostionTreeNode(k.node.left!!, k.postion * 2, k.depth+1))
+            }
+            if (k.node.right != null) {
+                queue.offer(PostionTreeNode(k.node.right!!, k.postion * 2 + 1, k.depth+1))
+            }
+        }
+        return maxWidth
+    }
+
+    class PostionTreeNode(val node: TreeNode, val postion: Int, val depth: Int)
+
+    @Test
+    fun test() {
+//        [1,3,2,5,null,null,9,6,null,7]
+        val root = TreeNode(1)
+        val node1 = TreeNode(3)
+        val node2 = TreeNode(2)
+        val node3 = TreeNode(5)
+        val node4 = TreeNode(5)
+        val node5 = TreeNode(5)
+        val node6 = TreeNode(5)
+
+        root.left = node1
+        root.right = node2
+
+        node1.left = node3
+        node3.left = node4
+
+        node2.right = node5
+        node5.left = node6
+        widthOfBinaryTree(root)
+    }
+}