规范格式

leetcode/0563.Binary-Tree-Tilt/563. Binary Tree Tilt.go

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+package leetcode
+
+import "math"
+
+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 findTilt(root *TreeNode) int {
+	if root == nil {
+		return 0
+	}
+	sum := 0
+	findTiltDFS(root, &sum)
+	return sum
+}
+
+func findTiltDFS(root *TreeNode, sum *int) int {
+	if root == nil {
+		return 0
+	}
+	left := findTiltDFS(root.Left, sum)
+	right := findTiltDFS(root.Right, sum)
+	*sum += int(math.Abs(float64(left) - float64(right)))
+	return root.Val + left + right
+}

leetcode/0563.Binary-Tree-Tilt/563. Binary Tree Tilt_test.go

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+package leetcode
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/halfrost/LeetCode-Go/structures"
+)
+
+type question563 struct {
+	para563
+	ans563
+}
+
+// para 是参数
+// one 代表第一个参数
+type para563 struct {
+	one []int
+}
+
+// ans 是答案
+// one 代表第一个答案
+type ans563 struct {
+	one int
+}
+
+func Test_Problem563(t *testing.T) {
+
+	qs := []question563{
+
+		question563{
+			para563{[]int{}},
+			ans563{0},
+		},
+
+		question563{
+			para563{[]int{1}},
+			ans563{0},
+		},
+
+		question563{
+			para563{[]int{3, 9, 20, structures.NULL, structures.NULL, 15, 7}},
+			ans563{41},
+		},
+
+		question563{
+			para563{[]int{1, 2, 3, 4, structures.NULL, structures.NULL, 5}},
+			ans563{11},
+		},
+
+		question563{
+			para563{[]int{1, 2, 3, 4, structures.NULL, 5}},
+			ans563{11},
+		},
+	}
+
+	fmt.Printf("------------------------Leetcode Problem 563------------------------\n")
+
+	for _, q := range qs {
+		_, p := q.ans563, q.para563
+		fmt.Printf("【input】:%v      ", p)
+		root := structures.Ints2TreeNode(p.one)
+		fmt.Printf("【output】:%v      \n", findTilt(root))
+	}
+	fmt.Printf("\n\n\n")
+}

leetcode/0563.Binary-Tree-Tilt/README.md

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+# [563. Binary Tree Tilt](https://leetcode.com/problems/binary-tree-tilt/)
+
+
+## 题目:
+
+Given a binary tree, return the tilt of the **whole tree**.
+
+The tilt of a **tree node** is defined as the **absolute difference** between the sum of all left subtree node values and the sum of all right subtree node values. Null node has tilt 0.
+
+The tilt of the **whole tree** is defined as the sum of all nodes' tilt.
+
+**Example:**
+
+    Input: 
+             1
+           /   \
+          2     3
+    Output: 1
+    Explanation: 
+    Tilt of node 2 : 0
+    Tilt of node 3 : 0
+    Tilt of node 1 : |2-3| = 1
+    Tilt of binary tree : 0 + 0 + 1 = 1
+
+**Note:**
+
+1. The sum of node values in any subtree won't exceed the range of 32-bit integer.
+2. All the tilt values won't exceed the range of 32-bit integer.
+
+
+## 题目大意
+
+
+给定一个二叉树，计算整个树的坡度。一个树的节点的坡度定义即为，该节点左子树的结点之和和右子树结点之和的差的绝对值。空结点的的坡度是0。整个树的坡度就是其所有节点的坡度之和。
+
+注意:
+
+1. 任何子树的结点的和不会超过32位整数的范围。
+2. 坡度的值不会超过32位整数的范围。
+
+## 解题思路
+
+
+- 给出一棵树，计算每个节点的“倾斜度”累加和。“倾斜度”的定义是：左子树和右子树的节点值差值的绝对值。
+- 这一题虽然是简单题，但是如果对题目中的“倾斜度”理解的不对，这一题就会出错。“倾斜度”计算的是左子树所有节点的值总和，和，右子树所有节点的值总和的差值。并不是只针对一个节点的左节点值和右节点值的差值。这一点明白以后，这一题就是简单题了。