main.go

@@ -2,49 +2,54 @@ package main
 
 import "fmt"
 
-func isMapEqual(a map[uint8]int, b map[uint8]int) bool {
+// ListNode Definition for singly-linked list.
-	for k, v := range a {
+type ListNode struct {
-		if val, ok := b[k]; ok {
+	Val  int
-			if val != v {
+	Next *ListNode
+}
+
+func isPalindrome(head *ListNode) bool {
+	srcHead := head
+	head = head.Next
+	// var left, right *ListNode
+	cnt := 1
+	for head != nil {
+		head = head.Next
+		cnt++
+	}
+	head = srcHead.Next
+	lastNode := srcHead
+	srcHead.Next = nil
+	half := cnt / 2
+	half--
+	for range half {
+		p := head.Next
+		head.Next = lastNode
+		lastNode = head
+		head = p
+	}
+	if cnt&1 == 1 {
+		head = head.Next
+	}
+	for head != nil && lastNode != nil {
+		if head.Val != lastNode.Val {
 			return false
 		}
-		} else {
+		head = head.Next
-			return false
+		lastNode = lastNode.Next
 	}
-	}
+	if head != nil || lastNode != nil {
-	for k, v := range b {
-		if val, ok := a[k]; ok {
-			if val != v {
-				return false
-			}
-		} else {
-			return false
-		}
-	}
-	return true
-}
-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 main() {
-	fmt.Printf("%v", checkStrings("abcdba", "cabdab"))
+	isPalindrome := isPalindrome(&ListNode{
+		Val: 1,
+		Next: &ListNode{
+			Val: 2,
+		},
+	})
+	fmt.Printf("isPalindrome: %v\n", isPalindrome)
 }