AC https://leetcode-cn.com/problems/palindrome-linked-list

Author: AaronLinRC

src/main/kotlin/leetcode/palindrome-linked-list/Solution.kt

@@ -0,0 +1,48 @@
+package leetcode.`palindrome-linked-list`
+
+import ListNode
+
+class Solution {
+    fun isPalindrome(head: ListNode?): Boolean {
+        if (head?.next == null) return true
+        var slowP = head
+        var fastP = head
+        while (fastP != null) {
+            slowP = slowP?.next
+            fastP = fastP.next?.next
+        }
+        var lastP: ListNode? = null
+        while (slowP != null) {
+            val next = slowP.next
+            slowP.next = lastP
+            lastP = slowP
+            slowP = next
+        }
+        var startP = head
+        while (startP != null && lastP != null) {
+            if (startP.`val` != lastP.`val`) return false
+            startP = startP.next
+            lastP = lastP.next
+        }
+
+        return true
+    }
+
+//    fun isPalindrome(head: ListNode?): Boolean {
+//        if (head?.next == null) return true
+//        val stack = Stack<Int>()
+//        var tag = head
+//        while (tag != null) {
+//            stack.push(tag.`val`)
+//            tag = tag.next
+//        }
+//        var start = head
+//        while (start != null) {
+//            if (start.`val` != stack.pop()) {
+//                return false
+//            }
+//            start = start.next
+//        }
+//        return true
+//    }
+}

src/main/kotlin/util/ListNode.kt

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+package util

src/main/kotlin/util/ListNodeUtil.kt

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+package util
+
+object ListNodeUtil {
+    fun generate(){
+
+    }
+}