148. 排序链表

go.mod

@@ -0,0 +1,3 @@
+module lichx.top/go-test
+
+go 1.25.0

list.go

@@ -0,0 +1,27 @@
+package main
+
+import "fmt"
+
+type ListNode struct {
+	Val  int
+	Next *ListNode
+}
+
+func makeLink(arr []int) *ListNode {
+	if len(arr) == 0 {
+		return nil
+	}
+	head := &ListNode{}
+	cur := head
+	for _, v := range arr {
+		cur.Next = &ListNode{Val: v}
+		cur = cur.Next
+	}
+	return head.Next
+}
+func checkLink(head *ListNode) {
+	for head != nil {
+		fmt.Println(head.Val)
+		head = head.Next
+	}
+}

main.go

@@ -1,50 +1,62 @@
 package main
 
-import "fmt"
-
-func isMapEqual(a map[uint8]int, b map[uint8]int) bool {
-	for k, v := range a {
-		if val, ok := b[k]; ok {
-			if val != v {
-				return false
+func conquerAndSort(head *ListNode, end *ListNode) *ListNode {
+	if head == nil || head == end || head.Next == nil {
+		return head
 	}
+	if head.Next == end {
+		if end != nil {
+			if head.Val > end.Val {
+				head.Val, end.Val = end.Val, head.Val
+			}
+		}
+		return head
+	}
+	if head.Next.Next == end {
+		if head.Val > head.Next.Val {
+			head.Next.Val, head.Val = head.Val, head.Next.Val
+		}
+		return head
+	}
+	slow, fast := head, head
+	for fast.Next != nil && fast.Next.Next != nil {
+		slow = slow.Next
+		fast = fast.Next.Next
+	}
+	lastSlow := slow
+	slow = slow.Next
+	lastSlow.Next = nil
+	a := conquerAndSort(head, nil)
+	b := conquerAndSort(slow, end)
+	if a.Val > b.Val {
+		a, b = b, a
+	}
+	// a Val < b Val
+	head = a
+	cur := a
+	a = a.Next
+	for a != nil && b != nil {
+		if a.Val > b.Val {
+			cur.Next = b
+			b = b.Next
 		} else {
-			return false
+			cur.Next = a
+			a = a.Next
 		}
+		cur = cur.Next
 	}
-	for k, v := range b {
-		if val, ok := a[k]; ok {
-			if val != v {
-				return false
-			}
+	if a == nil {
+		cur.Next = b
 	} else {
-			return false
+		cur.Next = a
 	}
-	}
-	return true
+	return head
 }
-func checkStrings(s1 string, s2 string) bool {
-	mp1 := make(map[uint8]int)
-	mp2 := make(map[uint8]int)
-	for i := 0; i < len(s1); i += 2 {
-		mp1[s1[i]]++
-		mp2[s2[i]]++
-	}
-	if !isMapEqual(mp1, mp2) {
-		return false
-	}
-	mp1 = make(map[uint8]int)
-	mp2 = make(map[uint8]int)
-	for i := 1; i < len(s1); i += 2 {
-		mp1[s1[i]]++
-		mp2[s2[i]]++
-	}
-	if !isMapEqual(mp1, mp2) {
-		return false
-	}
-	return true
+func sortList(head *ListNode) *ListNode {
+	return conquerAndSort(head, nil)
 }
 
 func main() {
-	fmt.Printf("%v", checkStrings("abcdba", "cabdab"))
+	arr := []int{-1, 5, 3, 4, 0}
+	checkLink(sortList(makeLink(arr)))
 }