92. 反转链表 II

go.mod

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

main.go

@@ -2,49 +2,77 @@ 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
-			}
-		} else {
-			return false
-		}
-	}
-	for k, v := range b {
-		if val, ok := a[k]; ok {
-			if val != v {
-				return false
-			}
-		} else {
-			return false
-		}
-	}
-	return true
+/**
+ * Definition for singly-linked list.*/
+type ListNode struct {
+	Val  int
+	Next *ListNode
 }
-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]]++
+
+func makeLink(arr []int) *ListNode {
+	if len(arr) == 0 {
+		return nil
 	}
-	if !isMapEqual(mp1, mp2) {
-		return false
+	head := &ListNode{}
+	cur := head
+	for _, v := range arr {
+		cur.Next = &ListNode{Val: v}
+		cur = cur.Next
 	}
-	mp1 = make(map[uint8]int)
-	mp2 = make(map[uint8]int)
-	for i := 1; i < len(s1); i += 2 {
-		mp1[s1[i]]++
-		mp2[s2[i]]++
+	return head.Next
+}
+func checkLink(head *ListNode) {
+	for head != nil {
+		fmt.Println(head.Val)
+		head = head.Next
 	}
-	if !isMapEqual(mp1, mp2) {
-		return false
+}
+
+func reverseBetween(head *ListNode, left int, right int) *ListNode {
+	if head.Next == nil {
+		return head
 	}
-	return true
+	left--
+	right--
+	cur_idx := 0
+	cur := head
+	var left_node *ListNode
+	var left_pre_node *ListNode = nil
+	_ = left_pre_node
+	var last_node *ListNode = nil
+	do_rev := false
+
+	for {
+		if cur_idx == left {
+			left_node = cur
+			left_pre_node = last_node
+			do_rev = true
+		}
+		next := cur.Next
+		if do_rev {
+			next = cur.Next
+			cur.Next = last_node
+			if cur_idx == right {
+				left_node.Next = next
+				if left_pre_node != nil {
+					left_pre_node.Next = cur
+				} else {
+					head = cur
+				}
+				do_rev = false
+			}
+		}
+		last_node = cur
+		cur = next
+		cur_idx++
+		if cur == nil {
+			break
+		}
+	}
+	return head
 }
 
 func main() {
-	fmt.Printf("%v", checkStrings("abcdba", "cabdab"))
+	arr := []int{3, 5}
+	checkLink(reverseBetween(makeLink(arr), 1, 2))
 }