104. Maximum Depth of Binary Tree

leetcode/0104.Maximum-Depth-of-Binary-Tree/104. Maximum Depth of Binary Tree.go

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+package leetcode
+
+import "github.com/blueBlue0102/LeetCode-Go/structures"
+
+func MaximumDepthofBinaryTree(root *structures.TreeNode) int {
+	height := 0
+	if root != nil {
+		height++
+		height += max(MaximumDepthofBinaryTree(root.Left), MaximumDepthofBinaryTree(root.Right))
+	}
+	return height
+}

leetcode/0104.Maximum-Depth-of-Binary-Tree/104. Maximum Depth of Binary Tree_test.go

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+package leetcode
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/blueBlue0102/LeetCode-Go/structures"
+)
+
+// 填入 function input type
+type parameters0104 struct {
+	root *structures.TreeNode
+}
+
+func TestMaximumDepthofBinaryTree(t *testing.T) {
+	tests := []struct {
+		parameters0104
+		// 填入 function output type
+		ans int
+	}{
+		// 填入 test case
+		{
+			parameters0104{structures.Ints2TreeNode([]int{3, 9, 20, structures.NULL, structures.NULL, 15, 7})},
+			3,
+		},
+		{
+			parameters0104{structures.Ints2TreeNode([]int{1, structures.NULL, 2})},
+			2,
+		},
+	}
+
+	for _, test := range tests {
+		t.Run("Test MaximumDepthofBinaryTree", func(t *testing.T) {
+			// 完整輸入參數
+			result := MaximumDepthofBinaryTree(test.parameters0104.root)
+			// compare 的方式需視情況調整
+			if !reflect.DeepEqual(result, test.ans) {
+				t.Errorf("MaximumDepthofBinaryTree(%+v) got %+v, want %+v", test.parameters0104, result, test.ans)
+			}
+		})
+	}
+}

leetcode/0104.Maximum-Depth-of-Binary-Tree/README.md

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+# 104. Maximum Depth of Binary Tree
+
+<https://leetcode.com/problems/maximum-depth-of-binary-tree/>
+
+給定一棵 Binary Tree，求樹的最大高度  
+（若只有 root 則高度為 1）
+
+樹需要從 root 開始進行遍歷，但位於 root 時並無法得知右或左子樹能否達到最遠節點  
+所以勢必需要遍歷整棵樹
+
+要用 pre 或 in-order 都無所謂，因為勢必就是需要遍歷每個節點
+
+## Takeaway
+
+- Tree Traversal