Day20 二叉树的深度遍历的递归实现

很久没写代码了，今天开始康复学习，今天就主要是递归 心得懒得写了

  1 public class BinaryCharTree {
  2     /**
  3      * The value in char.
  4      */
  5     char value;
  6 
  7     /**
  8      * The left child
  9      */
 10     BinaryCharTree leftChild;
 11 
 12     /**
 13      * The right child
 14      */
 15     BinaryCharTree rigthChild;
 16 
 17     /**
 18      * The first construcotr
 19      * 
 20      * @param paraName The value.
 21      */
 22     public BinaryCharTree(char paraName) {
 23         value = paraName;
 24         leftChild = null;
 25         rigthChild = null;
 26     }// Of the constructor
 27 
 28     /**
 29      * Manually construct a tree. Only for testing.
 30      * 
 31      * @return
 32      */
 33     public static BinaryCharTree manualConstructTree() {
 34         // step 1. Construct a tree with only one node.
 35         BinaryCharTree resultTree = new BinaryCharTree('a');
 36 
 37         // Step 2. Construct all nodes. The first node is the root.
 38         BinaryCharTree tempTreeB = new BinaryCharTree('b');
 39         BinaryCharTree tempTreeC = new BinaryCharTree('c');
 40         BinaryCharTree tempTreeD = new BinaryCharTree('d');
 41         BinaryCharTree tempTreeE = new BinaryCharTree('e');
 42         BinaryCharTree tempTreeF = new BinaryCharTree('f');
 43         BinaryCharTree tempTreeG = new BinaryCharTree('g');
 44 
 45         // Step 3. Link all nodes.
 46         resultTree.leftChild = tempTreeB;
 47         resultTree.rigthChild = tempTreeC;
 48         tempTreeB.rigthChild = tempTreeD;
 49         tempTreeC.leftChild = tempTreeE;
 50         tempTreeD.leftChild = tempTreeF;
 51         tempTreeD.rigthChild = tempTreeG;
 52 
 53         return resultTree;
 54     }// Of manualConstructTree
 55 
 56     /**
 57      * Pre-order visit.
 58      */
 59     public void preOrderVisit() {
 60         System.out.println("" + value + "");
 61 
 62         if (leftChild != null) {
 63             leftChild.preOrderVisit();
 64         } // Of if
 65 
 66         if (rigthChild != null) {
 67             rigthChild.preOrderVisit();
 68         } // Of if
 69     }// Of preOrderVisit
 70 
 71     /**
 72      * In-order visit.
 73      */
 74     public void inOrderVisit() {
 75         if (leftChild != null) {
 76             leftChild.inOrderVisit();
 77         } // Of if
 78 
 79         System.out.println("" + value + "");
 80 
 81         if (rigthChild != null) {
 82             rigthChild.inOrderVisit();
 83         } // Of if
 84     }// Of inOrderVisit
 85 
 86     /**
 87      * Post-order Visit.
 88      */
 89     public void postOrderVisit() {
 90         if (leftChild != null) {
 91             leftChild.postOrderVisit();
 92         } // Of if
 93 
 94         if (rigthChild != null) {
 95             rigthChild.postOrderVisit();
 96         } // Of if
 97 
 98         System.out.println("" + value + "");
 99     }// Of postVisit
100 
101     /**
102      * Get the depth of the binary tree
103      * 
104      * @return The depth. It is 1if there is only one node.
105      */
106     public int getDepth() {
107         if ((leftChild == null) && (rigthChild == null)) {
108             return 1;
109         } // Of if
110 
111         // The depth of the left child
112         int tempLeftDepth = 0;
113         if (leftChild != null) {
114             tempLeftDepth = leftChild.getDepth();
115         } // Of if
116 
117         // The depth of the right child
118         int tempRightDepth = 0;
119         if (rigthChild != null) {
120             tempRightDepth = rigthChild.getDepth();
121         } // Of if
122 
123         // The depth should increase by 1
124         if (tempLeftDepth >= tempRightDepth) {
125             return tempLeftDepth + 1;
126         } else {
127             return tempRightDepth + 1;
128         } // Of if
129     } // Of getDepth
130 
131     /**
132      * Get the number of nodes.
133      * 
134      * @return The number of nodes.
135      */
136     public int getNumNodes() {
137         // It is a leaf.
138         if ((leftChild == null) && (rigthChild == null)) {
139             return 1;
140         } // Of if
141 
142         // The number of nodes of the left child.
143         int tempLeftNodes = 0;
144         if (leftChild != null) {
145             tempLeftNodes = leftChild.getNumNodes();
146         } // Of if
147 
148         // The number of nodes of the rigth child.
149         int tempRightNodes = 0;
150         if (rigthChild != null) {
151             tempRightNodes = rigthChild.getNumNodes();
152         } // of if
153 
154         // The total number of nodes.
155         return tempLeftNodes + tempRightNodes + 1;
156     }// Of getNumNodes
157 
158     public static void main(String[] args) {
159         BinaryCharTree tempTree  = manualConstructTree();
160         System.out.println("\r\nPreorder visit:");
161         tempTree.preOrderVisit();
162         System.out.println("\r\nIn-Order visit:");
163         tempTree.inOrderVisit();
164         System.out.println("\r\nPost-Order visit:");
165         tempTree.postOrderVisit();
166 
167         System.out.println("\r\n\r\nThe depth is: " + tempTree.getDepth());
168         tempTree.getDepth();
169         System.out.println("The number of nodes is: " + tempTree.getNumNodes());
170     }// Of main
171 }// Of BinaryCharTree

 

 

posted @ 2022-08-11 19:09  滑稽的炒饭  阅读(25)  评论(0)    收藏  举报