规范格式

leetcode/0404.Sum-of-Left-Leaves/404. Sum of Left Leaves.go

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+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 sumOfLeftLeaves(root *TreeNode) int {
+	if root == nil {
+		return 0
+	}
+	if root.Left != nil && root.Left.Left == nil && root.Left.Right == nil {
+		return root.Left.Val + sumOfLeftLeaves(root.Right)
+	}
+	return sumOfLeftLeaves(root.Left) + sumOfLeftLeaves(root.Right)
+}

leetcode/0404.Sum-of-Left-Leaves/404. Sum of Left Leaves_test.go

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+package leetcode
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/halfrost/LeetCode-Go/structures"
+)
+
+type question404 struct {
+	para404
+	ans404
+}
+
+// para 是参数
+// one 代表第一个参数
+type para404 struct {
+	one []int
+}
+
+// ans 是答案
+// one 代表第一个答案
+type ans404 struct {
+	one int
+}
+
+func Test_Problem404(t *testing.T) {
+
+	qs := []question404{
+
+		question404{
+			para404{[]int{}},
+			ans404{0},
+		},
+
+		question404{
+			para404{[]int{3, 9, 20, structures.NULL, structures.NULL, 15, 7}},
+			ans404{24},
+		},
+	}
+
+	fmt.Printf("------------------------Leetcode Problem 404------------------------\n")
+
+	for _, q := range qs {
+		_, p := q.ans404, q.para404
+		fmt.Printf("【input】:%v      ", p)
+		root := structures.Ints2TreeNode(p.one)
+		fmt.Printf("【output】:%v      \n", sumOfLeftLeaves(root))
+	}
+	fmt.Printf("\n\n\n")
+}

leetcode/0404.Sum-of-Left-Leaves/README.md

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+# [404. Sum of Left Leaves](https://leetcode.com/problems/sum-of-left-leaves/)
+
+
+## 题目
+
+Find the sum of all left leaves in a given binary tree.
+
+**Example:**
+
+        3
+       / \
+      9  20
+        /  \
+       15   7
+    
+    There are two left leaves in the binary tree, with values 9 and 15 respectively. Return 24.
+
+
+## 题目大意
+
+计算给定二叉树的所有左叶子之和。
+
+
+## 解题思路
+
+
+- 这一题是微软的面试题。递归求解即可
+