From 4d1525b9a193b798e5792788def3e05bd562bf5f Mon Sep 17 00:00:00 2001
From: wangzheng <wangzheng>
Date: Tue, 2 Oct 2018 23:42:34 +0800
Subject: [PATCH] 06_linkedlist

---
 java/06_linkedlist/SinglyLinkedList.java | 150 +++++++++++++++++++++++
 1 file changed, 150 insertions(+)
 create mode 100644 java/06_linkedlist/SinglyLinkedList.java

diff --git a/java/06_linkedlist/SinglyLinkedList.java b/java/06_linkedlist/SinglyLinkedList.java
new file mode 100644
index 00000000..3978c0b4
--- /dev/null
+++ b/java/06_linkedlist/SinglyLinkedList.java
@@ -0,0 +1,150 @@
+package linkedlist;
+
+/**
+ * 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：Zheng
+ */
+public class SinglyLinkedList {
+
+  private Node head = null;
+
+  public Node findByValue(int value) {
+    Node p = head;
+    while (p != null && p.data != value) {
+      p = p.next;
+    }
+
+    return p;
+  }
+
+  public Node findByIndex(int index) {
+    Node p = head;
+    int pos = 0;
+    while (p != null && pos != index) {
+      p = p.next;
+      ++pos;
+    }
+
+    return p;
+  }
+
+  public void insertToHead(int value) {
+    Node newNode = new Node(value, null);
+    insertToHead(newNode);
+  }
+
+  public void insertToHead(Node newNode) {
+  if (head == null) {
+     head = newNode;
+    } else {
+      newNode.next = head;
+      head = newNode;
+    }
+  }
+
+  public void insertAfter(Node p, int value) {
+    Node newNode = new Node(value, null);
+    insertAfter(p, newNode);
+  }
+
+  public void insertAfter(Node p, Node newNode) {
+    if (p == null) return;
+
+    newNode.next = p.next;
+    p.next = newNode;
+  }
+
+  public void insertBefore(Node p, int value) {
+    Node newNode = new Node(value, null);
+    insertBefore(p, newNode);
+  }
+
+  public void insertBefore(Node p, Node newNode) {
+    if (p == null) return;
+    if (head == p) {
+      insertToHead(newNode);
+      return;
+    }
+
+    Node q = head;
+    while (q != null && q.next != p) {
+      q = q.next;
+    }
+
+    if (q == null) {
+      return;
+    }
+
+    newNode.next = p;
+    q.next = newNode;
+
+  }
+
+  public void deleteByNode(Node p) {
+    if (p == null || head == null) return;
+
+    if (p == head) {
+      head = head.next;
+    }
+
+    Node q = head;
+    while (q != null && q.next != p) {
+      q = q.next;
+    }
+
+    if (q == null) {
+      return;
+    }
+
+    q.next = q.next.next;
+  }
+
+  public void deleteByValue(int value) {
+    if (head == null) return;
+
+    Node p = head;
+    Node q = 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;
+    }
+  }
+
+  public void printAll() {
+    Node p = head;
+    while (p != null) {
+      System.out.print(p.data + " ");
+      p = p.next;
+    }
+    System.out.println();
+  }
+
+  public static Node createNode(int value) {
+    return new Node(value, null);
+  }
+
+  public static class Node {
+    private int data;
+    private Node next;
+
+    public Node(int data, Node next) {
+      this.data = data;
+      this.next = next;
+    }
+
+    public int getData() {
+      return data;
+    }
+  }
+
+}