Pretty code

Author: beyondyyh

algorithms/README.md

@@ -2,21 +2,21 @@
 
 | No. | Title | Go | <span id="Top">Difficulty</span> |
 |-----| ----- | -- | ---------- |
-|0001|[两数之和](https://leetcode-cn.com/problems/two-sum/)|[go](./myarray/1.twoSum.go)|<font color="#009975">S</font>|
-|0002|[两数相加](https://leetcode-cn.com/problems/add-two-numbers/)|[go](./linkedList/2.addTwoNumbers.go)|<font color="#ed7336">M</font>|
-|0003|[无重复字符的最长子串](https://leetcode-cn.com/problems/longest-substring-without-repeating-characters/)|[go](./mystring/3.lengthOfLongestSubstring.go)|<font color="#ed7336">M</font>|
-|0005|[最长回文子串](https://leetcode-cn.com/problems/longest-palindromic-substring/)|[go](./mystring/5.longestPalindrome.go)|<font color="#ed7336">M</font>|
+|0001|[两数之和](https://leetcode-cn.com/problems/two-sum/)|[go](./myarray/1.twoSum.go)|S|
+|0002|[两数相加](https://leetcode-cn.com/problems/add-two-numbers/)|[go](./linkedList/2.addTwoNumbers.go)|M|
+|0003|[无重复字符的最长子串](https://leetcode-cn.com/problems/longest-substring-without-repeating-characters/)|[go](./mystring/3.lengthOfLongestSubstring.go)|M|
+|0005|[最长回文子串](https://leetcode-cn.com/problems/longest-palindromic-substring/)|[go](./mystring/5.longestPalindrome.go)|M|
 |0007|[整数反转](https://leetcode-cn.com/problems/reverse-integer/)|[go](./mystring/7.reverse.go)|S|
-|0008|[字符串转换整数 (atoi)](https://leetcode-cn.com/problems/string-to-integer-atoi/)|[go](./mystring/8.myAtoi.go)|<font color="#ed7336">M</font>|
-|0011|[盛最多水的容器](https://leetcode-cn.com/problems/container-with-most-water/submissions/)|[go](./myarray/11.maxArea.go)|<font color="red">M</font>|
+|0008|[字符串转换整数 (atoi)](https://leetcode-cn.com/problems/string-to-integer-atoi/)|[go](./mystring/8.myAtoi.go)|M|
+|0011|[盛最多水的容器](https://leetcode-cn.com/problems/container-with-most-water/submissions/)|[go](./myarray/11.maxArea.go)|M|
 |0014|[最长公共前缀](https://leetcode-cn.com/problems/longest-common-prefix/)|[go](./mystring/14.longestCommonPrefix.go)|S|
-|0015|[三数之和](https://leetcode-cn.com/problems/3sum/submissions/)|[go](./myarray/15.threeSum.go)|<font color="red">M</font>|
-|0019|[删除链表的倒数第N个节点](https://leetcode-cn.com/problems/remove-nth-node-from-end-of-list/)|[go](./linkedList/19.removeNthFromEnd.go)|<font color="red">M</font>|
+|0015|[三数之和](https://leetcode-cn.com/problems/3sum/submissions/)|[go](./myarray/15.threeSum.go)|M|
+|0019|[删除链表的倒数第N个节点](https://leetcode-cn.com/problems/remove-nth-node-from-end-of-list/)|[go](./linkedList/19.removeNthFromEnd.go)|M|
 |0020|[有效的括号](https://leetcode-cn.com/problems/valid-parentheses/)|[go](./mystring/20.isValid.go)|S|
 |0021|[合并两个有序链表](https://leetcode-cn.com/problems/merge-two-sorted-lists/submissions/)|[go](./linkedList/21.mergeTwoSortedLists.go)|S|
-|0022|[括号生成](https://leetcode-cn.com/problems/generate-parentheses/)|[go](./tree/22.generateParenthesis.go)|<font color="red">M</font>|
+|0022|[括号生成](https://leetcode-cn.com/problems/generate-parentheses/)|[go](./tree/22.generateParenthesis.go)|M|
 |0026|[删除排序数组中的重复项](https://leetcode-cn.com/problems/remove-duplicates-from-sorted-array/)|[go](./myarray/26.removeDuplicates.go)|S|
-|0032|[最长有效括号](https://leetcode-cn.com/problems/longest-valid-parentheses/)|[go](./mystring/32.longestValidParentheses.go)|<font color="#ec4c47">H</font>|
+|0032|[最长有效括号](https://leetcode-cn.com/problems/longest-valid-parentheses/)|[go](./mystring/32.longestValidParentheses.go)|M|
 |0033|[搜索旋转排序数组](https://leetcode-cn.com/problems/search-in-rotated-sorted-array/submissions/)|[go](./myarray/33.search.go)|M|
 |0034|[在排序数组中查找元素的第一个和最后一个位置](https://leetcode-cn.com/problems/find-first-and-last-position-of-element-in-sorted-array/)|[go](./myarray/34.searchRange.go)|M|
 |0053|[最大子序和](https://leetcode-cn.com/problems/maximum-subarray/)|[go](./myarray/53.maxSubArray.go)|S|

algorithms/tree/102.levelOrder.go

@@ -1,6 +1,6 @@
 package tree
 
-// 普通的BFS遍历
+// BFS 普通的BFS遍历
 func BFS(root *TreeNode) []int { // {{{
 	var res []int
 	var queue []*TreeNode = []*TreeNode{root}
@@ -26,7 +26,7 @@ func BFS(root *TreeNode) []int { // {{{
 
 // 1. 普通的BFS 比较简单 只需要什么一个[]int 一个存放tree的队列 利用queue先进先出的规则打印value即可
 // 2. 如果根据等级来保存[][]int的话 只要声明一个正在遍历的队列 一个保存下一层节点的队列即可
-func levelOrder(root *TreeNode) [][]int { // {{{
+func levelOrder1(root *TreeNode) [][]int { // {{{
 	var res [][]int
 	var queue []*TreeNode = []*TreeNode{root}
 	if root == nil {
@@ -54,3 +54,25 @@ func levelOrder(root *TreeNode) [][]int { // {{{
 	}
 	return res
 } // }}}
+
+func levelOrder2(root *TreeNode) [][]int {
+	var res [][]int
+	var dfs func(*TreeNode, int)
+
+	dfs = func(root *TreeNode, level int) {
+		if root == nil {
+			return
+		}
+		// 出现了新的level
+		if level >= len(res) {
+			res = append(res, []int{})
+		}
+		res[level] = append(res[level], root.Val)
+
+		dfs(root.Left, level+1)
+		dfs(root.Right, level+1)
+	}
+
+	dfs(root, 0)
+	return res
+}

algorithms/tree/102.levelOrder_test.go

@@ -1,16 +1,42 @@
 package tree
 
 import (
-	_ "fmt"
 	"testing"
 
+	"github.com/stretchr/testify/assert"
+
 	"Leetcode/algorithms/kit"
 )
 
 // go test -v base.go 102.*
 func Test_levelOrder(t *testing.T) {
-	ints := []int{3, 9, 20, NULL, NULL, 15, 7}
-	tests := kit.Ints2Tree(ints)
-	t.Logf("case: %v\nBFS: %v\n levelOrder: %v\n",
-		kit.BreadthFirstSearch(*tests), BFS(tests), levelOrder(tests))
+	cases := []kit.CaseEntry{
+		{
+			Name:  "x1",
+			Input: []int{3, 9, 20, NULL, NULL, 15, 7},
+			Expected: [][]int{
+				[]int{3},
+				[]int{9, 20},
+				[]int{15, 7},
+			},
+		},
+		{
+			Name:  "x2",
+			Input: []int{3, 9, 20, 10, 11, 15, 7},
+			Expected: [][]int{
+				[]int{3},
+				[]int{9, 20},
+				[]int{10, 11, 15, 7},
+			},
+		},
+	}
+
+	assert := assert.New(t)
+	for _, c := range cases {
+		t.Run(c.Name, func(t *testing.T) {
+			root := kit.Ints2Tree(c.Input.([]int))
+			assert.Equal(c.Expected, levelOrder1(root), "Input:%v", c.Input)
+			assert.Equal(c.Expected, levelOrder2(root), "Input:%v", c.Input)
+		})
+	}
 }

algorithms/tree/104.maxDepth.go

@@ -10,7 +10,6 @@ func maxDepth(root *TreeNode) int {
 func max(a, b int) int {
 	if a >= b {
 		return a
-	} else {
-		return b
 	}
+	return b
 }

algorithms/tree/22.generateParenthesis.go

@@ -1,7 +1,5 @@
 package tree
 
-import _ "fmt"
-
 func generateParenthesis(n int) []string {
 	var res []string
 	if n == 0 {

algorithms/tree/base.go

@@ -2,9 +2,13 @@ package tree
 
 import "Leetcode/algorithms/kit"
 
+// NULL ...
 var NULL = kit.NULL
 
+// TreeNode ...
 type TreeNode = kit.TreeNode
+
+// Stack ...
 type Stack = kit.Stack
 
 // var TreeNode = kit.TreeNode

go.sum

@@ -2,6 +2,7 @@ github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
+github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=