add new files

Author: anakin

100. Same Tree.go

@@ -0,0 +1,21 @@
+package main
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func isSameTree(p *TreeNode, q *TreeNode) bool {
+
+	if p == nil && q == nil {
+		return true
+	}
+	if (p == nil && q != nil) || (p != nil && q == nil) {
+		return false
+	}
+	if p.Val != q.Val {
+		return false
+	}
+	return isSameTree(p.Left, q.Left) && isSameTree(p.Right, q.Right)
+}

114. Flatten Binary Tree to Linked List.go

@@ -0,0 +1,24 @@
+package main
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+//NB
+func flatten(root *TreeNode) {
+	node := root
+	for node != nil {
+		if node.Left != nil {
+			tmp := node.Left
+			for tmp.Right != nil {
+				tmp = tmp.Right
+			}
+			tmp.Right = node.Right
+			node.Right = node.Left
+			node.Left = nil
+		}
+		node = node.Right
+	}
+}

125. Valid Palindrome.go

@@ -0,0 +1,28 @@
+package main
+
+import (
+	"fmt"
+	"regexp"
+	"strings"
+)
+
+//TODO 速度不是很理想
+func isPalindrome1(s string) bool {
+	pat := "[,:.@#--?\";!` ]"
+	re, _ := regexp.Compile(pat)
+
+	s = re.ReplaceAllString(s, "")
+	s = strings.ToLower(s)
+	fmt.Println("s=", s)
+	if s == "" {
+		return true
+	}
+	j := len(s) - 1
+	for i := 0; i < len(s)/2; i++ {
+		if s[i] != s[j] {
+			return false
+		}
+		j--
+	}
+	return true
+}

136. Single Number.go

@@ -0,0 +1,13 @@
+package main
+
+//classic
+func singleNumber(nums []int) int {
+	if len(nums) == 1 {
+		return nums[0]
+	}
+	res := nums[0]
+	for i := 1; i < len(nums); i++ {
+		res ^= nums[i]
+	}
+	return res
+}

141. Linked List Cycle.go

@@ -0,0 +1,24 @@
+package main
+
+type ListNode struct {
+	Val  int
+	Next *ListNode
+}
+
+//快慢指针，如果相遇则有环
+func hasCycle(head *ListNode) bool {
+	if head == nil {
+		return false
+	}
+	fast := head.Next
+	slow := head
+
+	for slow != nil && fast != nil && fast.Next != nil {
+		slow = slow.Next
+		fast = fast.Next.Next
+		if fast == slow {
+			return true
+		}
+	}
+	return false
+}

144. Binary Tree Preorder Traversal.go

@@ -0,0 +1,27 @@
+package main
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+//前中后基本类似
+func preorderTraversal(root *TreeNode) []int {
+	res := []int{}
+	if root == nil {
+		return res
+	}
+	helper(&res, root)
+	return res
+}
+
+func helper(res *[]int, root *TreeNode) {
+	*res = append(*res, root.Val)
+	if root.Left != nil {
+		helper(res, root.Left)
+	}
+	if root.Right != nil {
+		helper(res, root.Right)
+	}
+}

145. Binary Tree Postorder Traversal.go

@@ -0,0 +1,26 @@
+package main
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func postorderTraversal(root *TreeNode) []int {
+	res := []int{}
+	if root == nil {
+		return res
+	}
+	helper(&res, root)
+	return res
+}
+
+func helper(res *[]int, root *TreeNode) {
+	if root.Left != nil {
+		helper(res, root.Left)
+	}
+	if root.Right != nil {
+		helper(res, root.Right)
+	}
+	*res = append(*res, root.Val)
+}

151. Reverse Words in a String.go

@@ -0,0 +1,23 @@
+package main
+
+import (
+	"fmt"
+	"strings"
+)
+
+//总觉得有更好的办法
+func reverseWords(s string) string {
+	arr := strings.Split(s, " ")
+	res := []string{}
+	for i := 0; i < len(arr); i++ {
+		if arr[i] != "" {
+			res = append(res, arr[i])
+		}
+	}
+	for i, j := 0, len(res)-1; i < j; i, j = i+1, j-1 {
+		res[i], res[j] = res[j], res[i]
+	}
+
+	return strings.Replace(strings.Trim(fmt.Sprint(res), "[]"), " ", " ", -1)
+
+}

155. Min Stack.go

@@ -0,0 +1,54 @@
+package main
+
+import "fmt"
+
+//TODO 逻辑没问题，但是通过不了越界的测试
+type MinStack struct {
+	cur  int
+	min  []int
+	data []int
+}
+
+/** initialize your data structure here. */
+func Constructor() MinStack {
+	min, data := []int{}, []int{}
+	return MinStack{
+		cur:  -1,
+		min:  min,
+		data: data,
+	}
+}
+
+func (this *MinStack) Push(x int) {
+	this.cur++
+	this.data = append(this.data, x)
+	if this.cur > 0 {
+		if x > this.min[this.cur-1] {
+			this.min = append(this.min, this.min[this.cur-1])
+		} else {
+			this.min = append(this.min, x)
+		}
+	} else {
+		this.min = append(this.min, x)
+	}
+	fmt.Println(this.min)
+}
+
+func (this *MinStack) Pop() {
+	this.cur--
+}
+
+func (this *MinStack) Top() int {
+	return this.data[this.cur]
+}
+
+func (this *MinStack) GetMin() int {
+	return this.min[this.cur]
+}
+
+func main() {
+	m := Constructor()
+	m.Push(-2)
+	m.Push(0)
+	m.Push(-1)
+}

94. Binary Tree Inorder Traversal.go

@@ -0,0 +1,26 @@
+package main
+
+type TreeNode struct {
+	Val   int
+	Left  *TreeNode
+	Right *TreeNode
+}
+
+func inorderTraversal(root *TreeNode) []int {
+	res := []int{}
+	if root == nil {
+		return res
+	}
+	helper(&res, root)
+	return res
+}
+func helper(res *[]int, root *TreeNode) {
+	if root.Left != nil {
+		helper(res, root.Left)
+	}
+	*res = append(*res, root.Val)
+	if root.Right != nil {
+		helper(res, root.Right)
+	}
+
+}