Merge pull request #335 from Zackratos/master

06_linkedlist kotlin version

Author: wangzheng0822

kotlin/06_linkedlist/SinglyLinkedList.kt

@@ -0,0 +1,293 @@
+/**
+ * 1）单链表的插入、删除、查找操作；
+ * 2）链表中存储的是int类型的数据；
+ *
+ * Author：Zackratos
+ */
+
+class SinglyLinkedList {
+
+    private var head: Node? = null
+
+    companion object {
+        @JvmStatic
+        fun main(args: Array<String>) {
+
+            val link = SinglyLinkedList()
+            println("hello")
+            val data = intArrayOf(1, 2, 5, 3, 1)
+
+            for (i in data.indices) {
+                //link.insertToHead(data[i]);
+                link.insertTail(data[i])
+            }
+
+            println("打印原始:")
+            link.printAll()
+            if (link.palindrome()) {
+                println("回文")
+            } else {
+                println("不是回文")
+            }
+        }
+    }
+
+    fun findByValue(value: Int): Node? {
+        var p = head
+        while (p != null && p.data != value) {
+            p = p.next
+        }
+
+        return p
+    }
+
+    fun findByIndex(index: Int): Node? {
+        var p = head
+        var pos = 0
+        while (p != null && pos != index) {
+            p = p.next
+            ++pos
+        }
+
+        return p
+    }
+
+    //无头结点
+    //表头部插入
+    //这种操作将于输入的顺序相反，逆序
+    fun insertToHead(value: Int) {
+        val newNode = Node(value, null)
+        insertToHead(newNode)
+    }
+
+    fun insertToHead(newNode: Node) {
+        if (head == null) {
+            head = newNode
+        } else {
+            newNode.next = head
+            head = newNode
+        }
+    }
+
+    //顺序插入
+    //链表尾部插入
+    fun insertTail(value: Int) {
+
+        val newNode = Node(value, null)
+        //空链表，可以插入新节点作为head，也可以不操作
+        if (head == null) {
+            head = newNode
+
+        } else {
+            var q = head
+            while (q?.next != null) {
+                q = q.next
+            }
+            newNode.next = q?.next
+            q?.next = newNode
+        }
+    }
+
+    fun insertAfter(p: Node?, value: Int) {
+        val newNode = Node(value, null)
+        insertAfter(p, newNode)
+    }
+
+    fun insertAfter(p: Node?, newNode: Node) {
+        if (p == null) return
+
+        newNode.next = p.next
+        p.next = newNode
+    }
+
+    fun insertBefore(p: Node?, value: Int) {
+        val newNode = Node(value, null)
+        insertBefore(p, newNode)
+    }
+
+    fun insertBefore(p: Node?, newNode: Node) {
+        if (p == null) return
+        if (head === p) {
+            insertToHead(newNode)
+            return
+        }
+
+        var q = head
+        while (q != null && q.next !== p) {
+            q = q.next
+        }
+
+        if (q == null) {
+            return
+        }
+
+        newNode.next = p
+        q.next = newNode
+
+    }
+
+    fun deleteByNode(p: Node?) {
+        if (p == null || head == null) return
+
+        if (p === head) {
+            head = head?.next
+            return
+        }
+
+        var q = head
+        while (q != null && q.next !== p) {
+            q = q.next
+        }
+
+        if (q == null) {
+            return
+        }
+
+        q.next = q.next?.next
+    }
+
+    fun deleteByValue(value: Int) {
+        if (head == null) return
+
+        var p = head
+        var q: Node? = null
+        while (p != null && p.data != value) {
+            q = p
+            p = p.next
+        }
+
+        if (p == null) return
+
+        if (q == null) {
+            head = head?.next
+        } else {
+            q.next = q.next?.next
+        }
+    }
+
+    fun printAll() {
+        var p = head
+        while (p != null) {
+            print("${p.data} ")
+            p = p.next
+        }
+        println()
+    }
+
+    //判断true or false
+    fun TFResult(left: Node?, right: Node?): Boolean {
+        var l: Node? = left
+        var r: Node? = right
+
+        println("left_:${l?.data}")
+        println("right_:${r?.data}")
+        while (l != null && r != null) {
+            if (l.data == r.data) {
+                l = l.next
+                r = r.next
+                continue
+            } else {
+                break
+            }
+
+        }
+
+        println("什么结果")
+        return l == null && r == null
+    }
+
+    //　判断是否为回文
+    fun palindrome(): Boolean {
+        if (head == null) {
+            return false
+        } else {
+            println("开始执行找到中间节点")
+            var p = head
+            var q = head
+            if (p?.next == null) {
+                println("只有一个元素")
+                return true
+            }
+            while (q?.next != null && q.next?.next != null) {
+                p = p?.next
+                q = q.next?.next
+            }
+
+            println("中间节点${p?.data}")
+            println("开始执行奇数节点的回文判断")
+            val leftLink: Node?
+            val rightLink: Node?
+            if (q?.next == null) {
+                //　p 一定为整个链表的中点，且节点数目为奇数
+                rightLink = p?.next
+                leftLink = inverseLinkList(p)?.next
+                println("左边第一个节点${leftLink?.data}")
+                println("右边第一个节点${rightLink?.data}")
+
+            } else {
+                //p q　均为中点
+                rightLink = p?.next
+                leftLink = inverseLinkList(p)
+            }
+            return TFResult(leftLink, rightLink)
+
+        }
+    }
+
+    //带结点的链表翻转
+    fun inverseLinkList_head(p: Node): Node {
+        //　Head　为新建的一个头结点
+        val Head = Node(9999, null)
+        // p　为原来整个链表的头结点,现在Head指向　整个链表
+        Head.next = p
+        /*
+        带头结点的链表翻转等价于
+        从第二个元素开始重新头插法建立链表
+        */
+        var Cur = p.next
+        p.next = null
+        var next: Node?
+
+        while (Cur != null) {
+            next = Cur.next
+            Cur.next = Head.next
+            Head.next = Cur
+            println("first " + Head.data)
+
+            Cur = next
+        }
+
+        //　返回左半部分的中点之前的那个节点
+        //　从此处开始同步像两边比较
+        return Head
+
+    }
+
+    //无头结点的链表翻转
+    fun inverseLinkList(p: Node?): Node? {
+
+        var pre: Node? = null
+        var r = head
+        println("z---${r?.data}")
+        var next: Node?
+        while (r !== p) {
+            next = r?.next
+
+            r?.next = pre
+            pre = r
+            r = next
+        }
+
+        r?.next = pre
+        //　返回左半部分的中点之前的那个节点
+        //　从此处开始同步像两边比较
+        return r
+
+    }
+
+    fun createNode(value: Int): Node = Node(value, null)
+
+
+
+    class Node(var data: Int, var next: Node?)
+}