二叉树最大深度，递归中序遍历，递归前序遍历，递归后序遍历，非递归中序遍历，非递归前序遍历，非递归后序遍历
二叉树最大深度，前序遍历、中序遍历、后序遍历算法，包含递归与非递归
1 import java.util.*; 2 3 import javax.swing.plaf.synth.SynthSpinnerUI; 4 class TreeNode{ 5 int data; 6 TreeNode lefchild=null; 7 TreeNode rightchild=null; 8 TreeNode(int data,TreeNode leftchild,TreeNode rightchild){ 9 this.data=data; 10 this.lefchild=leftchild; 11 this.rightchild=rightchild; 12 } 13 } 14 public class BinaryTree { 15 16 public static void main(String[] args) { 17 // TODO Auto-generated method stub 18 TreeNode J=new TreeNode(8,null,null); 19 TreeNode H=new TreeNode(4,null,null); 20 TreeNode G=new TreeNode(2,null,null); 21 TreeNode F=new TreeNode(7,null,J); 22 TreeNode E=new TreeNode(5,H,null); 23 TreeNode D=new TreeNode(1,null,G); 24 TreeNode C=new TreeNode(9,F,null); 25 TreeNode B=new TreeNode(3,D,E); 26 TreeNode A=new TreeNode(6,B,C); 27 BinaryTree p=new BinaryTree(); 28 int maxdepth=p.getMaxDepth(A); 29 System.out.println("最大深度："+maxdepth); 30 31 System.out.print("递归中序遍历："); 32 p.inorder(A); 33 System.out.println(); 34 System.out.print("非递归中序遍历："); 35 p.inOrder(A); 36 System.out.println(); 37 38 System.out.print("递归前序遍历："); 39 p.preorder(A); 40 System.out.println(); 41 System.out.print("非递归前序遍历："); 42 p.preOrder(A); 43 System.out.println(); 44 45 System.out.print("递归后序遍历："); 46 p.postorder(A); 47 System.out.println(); 48 System.out.print("非递归后序遍历："); 49 p.postOrder(A); 50 System.out.println(); 51 } 52 /*获取最大深度*/ 53 public int getMaxDepth(TreeNode root){ 54 if(root==null){ 55 return 0; 56 }else{ 57 int leftDepth=getMaxDepth(root.lefchild); 58 int rightDepth=getMaxDepth(root.rightchild); 59 return 1+Math.max(leftDepth, rightDepth); } 60 } 61 /*递归中序遍历*/ 62 public void inorder(TreeNode root){ 63 if(root==null){ 64 return; 65 }else{ 66 inorder(root.lefchild); 67 System.out.print(root.data+" "); 68 inorder(root.rightchild); 69 } 70 } 71 /*递归前序遍历*/ 72 public void preorder(TreeNode root){ 73 if(root==null){ 74 return; 75 }else{ 76 System.out.print(root.data+" "); 77 preorder(root.lefchild); 78 preorder(root.rightchild); 79 } 80 } 81 /*递归后序遍历*/ 82 public void postorder(TreeNode root){ 83 if(root==null){ 84 return; 85 }else{ 86 postorder(root.lefchild); 87 postorder(root.rightchild); 88 System.out.print(root.data+" "); 89 } 90 } 91 /*非递归中序遍历*/ 92 public void inOrder(TreeNode root){ 93 Stack<TreeNode> stack=new Stack<TreeNode>(); 94 while(root!=null||!stack.isEmpty()){ 95 while(root!=null){ 96 stack.push(root); 97 root=root.lefchild; 98 } 99 if(!stack.isEmpty()){ 100 root=stack.pop(); 101 System.out.print(root.data+" "); 102 root=root.rightchild; 103 } 104 } 105 } 106 /*非递归前序遍历*/ 107 public void preOrder(TreeNode root){ 108 Stack<TreeNode> stack=new Stack<TreeNode>(); 109 while(root!=null||!stack.isEmpty()){ 110 while(root!=null){ 111 System.out.print(root.data+" "); 112 stack.push(root); 113 root=root.lefchild; 114 } 115 if(!stack.isEmpty()){ 116 root=stack.pop(); 117 root=root.rightchild; 118 } 119 } 120 } 121 /*非递归后序遍历*/ 122 public void postOrder(TreeNode root){ 123 Stack<TreeNode> stack=new Stack<TreeNode>(); 124 TreeNode prev=null; 125 while(root!=null||!stack.isEmpty()){ 126 while(root!=null){ 127 stack.push(root); 128 root=root.lefchild; 129 } 130 if(!stack.isEmpty()){ 131 TreeNode temp=stack.peek().rightchild; 132 if(temp==null||temp==prev){ 133 root=stack.pop(); 134 prev=root; 135 System.out.print(root.data+" "); 136 root=null; 137 }else{ 138 root=temp; 139 } 140 } 141 } 142 } 143 }
