Added solution 543

leetcode/0543.Diameter-of-Binary-Tree/543. Diameter of Binary Tree.go

@@ -0,0 +1,47 @@
+package leetcode
+
+import (
+	"github.com/halfrost/LeetCode-Go/structures"
+)
+
+// TreeNode define
+type TreeNode = structures.TreeNode
+
+/**
+ * Definition for a binary tree node.
+ * type TreeNode struct {
+ *     Val int
+ *     Left *TreeNode
+ *     Right *TreeNode
+ * }
+ */
+
+func diameterOfBinaryTree(root *TreeNode) int {
+	result := 0
+
+	checkDiameter(root, &result)
+
+	return result
+}
+
+func checkDiameter(root *TreeNode, result *int) int {
+	if root == nil {
+		return 0
+	}
+
+	left := checkDiameter(root.Left, result)
+
+	right := checkDiameter(root.Right, result)
+
+	*result = max(*result, left+right)
+
+	return max(left, right) + 1
+}
+
+func max(a int, b int) int {
+	if a > b {
+		return a
+	}
+
+	return b
+}