我最近开始学习 Kotlin,所以我决定在其中实现一些数据结构。所以,我尝试实现一个单链表:
package datastructures
public class LinkedList {
private data class Node(var nodeValue: Int, var next: Node? = null)
private var head: Node? = null
fun insert(n: Int) {
if(head == null) head = Node(n)
else {
var cur = head
while(cur?.next != null) {
cur = cur?.next
}
cur?.next = Node(n)
}
}
fun print() {
var cur = head
while(cur != null) {
print("${cur.nodeValue} ")
cur = cur?.next
}
}
}
fun main(args: Array<String>) {
val n = LinkedList()
n.insert(5)
n.insert(3)
n.print()
}
我收到以下错误:
Error:(22, 13) Kotlin: [Internal Error] org.jetbrains.jet.codegen.CompilationException: Back-end (JVM) Internal error: cannot store to value org.jetbrains.jet.codegen.StackValue$OnStack@a0a447f
Cause: cannot store to value org.jetbrains.jet.codegen.StackValue$OnStack@a0a447f
File being compiled and position: (22,13) in C:/Users/Khaled/IdeaProjects/Kotlin/src/LinkedList.kt
PsiElement: cur?.next = Node(n)
The root cause was thrown at: StackValue.java:75
at org.jetbrains.jet.codegen.ExpressionCodegen.genQualified(ExpressionCodegen.java:243)
at org.jetbrains.jet.codegen.ExpressionCodegen.genStatement(ExpressionCodegen.java:262)
at ...
我一直在这里和谷歌搜索,但我不知道是什么问题导致了这个错误
编辑:
所以我尝试重新实现该insert
函数并使用requireNotNull()
以避免编译器担心空安全问题。
这是代码,它现在正在工作:
fun insert(n: Int) {
if (head == null) head = Node(n)
else {
var cur = head!!
while (cur.next != null) {
cur = cur.next!!
}
cur.next = Node(n)
}
}