feat(Kotlin): Replace value with _val (#1254)

* ci(kotlin): Add workflow file.

* Update kotlin.yml

* style(kotlin): value -> _val

---------

Co-authored-by: Yudong Jin <krahets@163.com>

codes/kotlin/utils/ListNode.kt

@@ -7,7 +7,7 @@
 package utils
 
 /* 链表节点 */
-class ListNode(var value: Int) {
+class ListNode(var _val: Int) {
     var next: ListNode? = null
 
     companion object {
@@ -15,8 +15,8 @@ class ListNode(var value: Int) {
         fun arrToLinkedList(arr: IntArray): ListNode? {
             val dum = ListNode(0)
             var head = dum
-            for (value in arr) {
-                head.next = ListNode(value)
+            for (_val in arr) {
+                head.next = ListNode(_val)
                 head = head.next!!
             }
             return dum.next

codes/kotlin/utils/PrintUtil.kt

@@ -33,7 +33,7 @@ fun printLinkedList(h: ListNode?) {
     var head = h
     val list = mutableListOf<String>()
     while (head != null) {
-        list.add(head.value.toString())
+        list.add(head._val.toString())
         head = head.next
     }
     println(list.joinToString(separator = " -> "))
@@ -70,7 +70,7 @@ fun printTree(root: TreeNode?, prev: Trunk?, isRight: Boolean) {
     }
 
     showTrunks(trunk)
-    println(" ${root.value}")
+    println(" ${root._val}")
 
     if (prev != null) {
         prev.str = prevStr

codes/kotlin/utils/TreeNode.kt

@@ -9,7 +9,7 @@ package utils
 /* 二叉树节点类 */
 /* 构造方法 */
 class TreeNode(
-    var value: Int // 节点值
+    var _val: Int // 节点值
 ) {
     var height: Int = 0 // 节点高度
     var left: TreeNode? = null // 左子节点引用
@@ -54,7 +54,7 @@ class TreeNode(
             while (i >= res.size) {
                 res.add(null)
             }
-            res[i] = root.value
+            res[i] = root._val
             treeToListDFS(root.left, 2 * i + 1, res)
             treeToListDFS(root.right, 2 * i + 2, res)
         }

codes/kotlin/utils/Vertex.kt

@@ -7,7 +7,7 @@
 package utils
 
 /* 顶点类 */
-class Vertex(val value: Int) {
+class Vertex(val _val: Int) {
     companion object {
         /* 输入值列表 vals ，返回顶点列表 vets */
         fun valsToVets(vals: IntArray): Array<Vertex?> {
@@ -22,7 +22,7 @@ class Vertex(val value: Int) {
         fun vetsToVals(vets: MutableList<Vertex?>): MutableList<Int> {
             val vals = mutableListOf<Int>()
             for (vet in vets) {
-                vals.add(vet!!.value)
+                vals.add(vet!!._val)
             }
             return vals
         }