Merge pull request #159 from brenobaptista/solution-543

Added solution 543

Author: halfrost

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
+}

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

@@ -0,0 +1,56 @@
+package leetcode
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/halfrost/LeetCode-Go/structures"
+)
+
+type question543 struct {
+	para543
+	ans543
+}
+
+// para 是参数
+// one 代表第一个参数
+type para543 struct {
+	one []int
+}
+
+// ans 是答案
+// one 代表第一个答案
+type ans543 struct {
+	one int
+}
+
+func Test_Problem543(t *testing.T) {
+
+	qs := []question543{
+
+		{
+			para543{[]int{1, 2, 3, 4, 5}},
+			ans543{3},
+		},
+
+		{
+			para543{[]int{1, 2}},
+			ans543{1},
+		},
+
+		{
+			para543{[]int{4, -7, -3, structures.NULL, structures.NULL, -9, -3, 9, -7, -4, structures.NULL, 6, structures.NULL, -6, -6, structures.NULL, structures.NULL, 0, 6, 5, structures.NULL, 9, structures.NULL, structures.NULL, -1, -4, structures.NULL, structures.NULL, structures.NULL, -2}},
+			ans543{8},
+		},
+	}
+
+	fmt.Printf("------------------------Leetcode Problem 543------------------------\n")
+
+	for _, q := range qs {
+		_, p := q.ans543, q.para543
+		fmt.Printf("【input】:%v      ", p)
+		root := structures.Ints2TreeNode(p.one)
+		fmt.Printf("【output】:%v      \n", diameterOfBinaryTree(root))
+	}
+	fmt.Printf("\n\n\n")
+}

leetcode/0543.Diameter-of-Binary-Tree/README.md

@@ -0,0 +1,31 @@
+# [543. Diameter of Binary Tree](https://leetcode.com/problems/diameter-of-binary-tree/)
+
+## 题目
+
+Given the `root` of a binary tree, return the length of the **diameter** of the tree.
+
+The **diameter** of a binary tree is the **length** of the longest path between any two nodes in a tree. This path may or may not pass through the `root`.
+
+The **length** of a path between two nodes is represented by the number of edges between them.
+
+**Example 1:**
+
+![https://assets.leetcode.com/uploads/2021/03/06/diamtree.jpg](https://assets.leetcode.com/uploads/2021/03/06/diamtree.jpg)
+
+```
+Input: root = [1,2,3,4,5]
+Output: 3
+Explanation: 3 is the length of the path [4,2,1,3] or [5,2,1,3].
+```
+
+**Example 2:**
+
+```
+Input: root = [1,2]
+Output: 1
+```
+
+**Constraints:**
+
+- The number of nodes in the tree is in the range `[1, 104]`.
+- `-100 <= Node.val <= 100`