Java學習(十八)：二叉樹的三種遞迴遍曆

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二叉樹的三種遞迴遍曆：

  1 public class StudentNode  2 {  3     private String name;  4       5     private StudentNode leftNode;  6       7     private StudentNode rightNode;  8       9     public String getName() 10     { 11         return name; 12     } 13      14     public void setName(String name) 15     { 16         this.name = name; 17     } 18      19     public StudentNode getLeftNode() 20     { 21         return leftNode; 22     } 23      24     public void setLeftNode(StudentNode leftNode) 25     { 26         this.leftNode = leftNode; 27     } 28      29     public StudentNode getRightNode() 30     { 31         return rightNode; 32     } 33      34     public void setRightNode(StudentNode rightNode) 35     { 36         this.rightNode = rightNode; 37     } 38      39     public static void main(String[] args) 40     { 41         StudentNode root = new StudentNode(); 42         root.setName("Name1"); 43         StudentNode node2 = new StudentNode(); 44         node2.setName("Name2"); 45         StudentNode node3 = new StudentNode(); 46         node3.setName("Name3"); 47         StudentNode node4 = new StudentNode(); 48         node4.setName("Name4"); 49         StudentNode node5 = new StudentNode(); 50         node5.setName("Name5"); 51         StudentNode node6 = new StudentNode(); 52         node6.setName("Name6"); 53         StudentNode node7 = new StudentNode(); 54         node7.setName("Name7"); 55         // 56         // ****root*** 57         // ***/ **\*** 58         // **2 ****5** 59         // */ \ **/*** 60         // 3 *4 **6*** 61         // *******\*** 62         // ********7** 63         // 64         root.setLeftNode(node2); 65         root.setRightNode(node5); 66         node2.setLeftNode(node3); 67         node2.setRightNode(node4); 68         node5.setLeftNode(node6); 69         node6.setRightNode(node7); 70          71         // 前序走訪1-2-3-4-5-6-7 72         rootFirst(root); 73         // 中序遍曆3-2-4-1-6-7-5 74         rootMiddle(root); 75         // 後序遍曆3-4-2-7-6-5-1 76         rootLast(root); 77     } 78      79     private static void rootFirst(StudentNode node) 80     { 81         System.out.println(node.getName()); 82         if (null != node.getLeftNode()) 83         { 84             rootFirst(node.getLeftNode()); 85         } 86         if (null != node.getRightNode()) 87         { 88             rootFirst(node.getRightNode()); 89         } 90     } 91      92     private static void rootMiddle(StudentNode node) 93     { 94         if (null != node.getLeftNode()) 95         { 96             rootMiddle(node.getLeftNode()); 97         } 98         System.out.println(node.getName()); 99         if (null != node.getRightNode())100         {101             rootMiddle(node.getRightNode());102         }103     }104     105     private static void rootLast(StudentNode node)106     {107         if (null != node.getLeftNode())108         {109             rootLast(node.getLeftNode());110         }111         if (null != node.getRightNode())112         {113             rootLast(node.getRightNode());114         }115         System.out.println(node.getName());116     }117 }

 

Java學習(十八)：二叉樹的三種遞迴遍曆