本文實例講述了Java實現的二叉樹常用操作。分享給大家供大家參考，具體如下：
import java.util.ArrayDeque;import java.util.Queue;import java.util.Stack;//二叉樹的建樹，前中後遞歸非遞歸遍歷層序遍歷//Node節點class Node { int element; Node left; Node right; public Node() { } public Node(int element) { this.element = element; }}// BinaryTreepublic class Tree { // creat tree from array public static Node creatTree(int[] data, int i) { if (i >= data.length || data[i] == -1) return null; Node temp = new Node(data[i]); temp.left = creatTree(data, i * 2 + 1); temp.right = creatTree(data, i * 2 + 2); return temp; } // pre前序遍歷遞歸public static void pre(Node temp) { if (temp == null) return; System.out.print(temp.element + " "); pre(temp.left); pre(temp.right); } // mid中序遍歷遞歸public static void mid(Node temp) { if (temp == null) return; mid(temp.left); System.out.print(temp.element + " "); mid(temp.right); } // last後序遍歷遞歸public static void last(Node temp) { if (temp == null) return; last(temp.left); last(temp.right); System.out.print(temp.element + " "); } // pre1前序遍歷非遞歸public static void pre1(Node temp) { Stack<Node> stack = new Stack<>(); while (temp != null || !stack.isEmpty()) { while (temp != null) { stack.push(temp); System.out.print(temp.element + " "); temp = temp.left; } if (!stack.isEmpty()) { temp = stack.pop().right; } } } // mid1中序遍歷非遞歸public static void mid1(Node temp) { Stack<Node> stack = new Stack<>(); while (temp != null || !stack.isEmpty()) { while (temp != null) { stack.push(temp); temp = temp.left; } if (!stack.isEmpty()) { temp = stack.pop(); System.out.print(temp.element + " "); temp = temp.right; } } } // last1後序遍歷非遞歸public static void last1(Node temp) { Stack<Node> stack = new Stack<>(); Stack<Node> stack2 = new Stack<>(); while (temp != null || !stack.isEmpty()) { while (temp != null) { stack.push(temp); stack2.push(temp); temp = temp.right; } if (!stack.isEmpty()) { temp = stack.pop().left; } } while (!stack2.isEmpty()) System.out.print(stack2.pop().element + " "); } // ceng層序遍歷public static void ceng(Node temp) { if (temp == null) return; Queue<Node> queue = new ArrayDeque<>(); queue.offer(temp); while (!queue.isEmpty()) { temp = queue.poll(); System.out.print(temp.element + " "); if (temp.left != null) queue.offer(temp.left); if (temp.right != null) queue.offer(temp.right); } } // Demo public static void main(String[] args) { int[] array = { 1, 2, 3, 4, 5, 6, 7, -1, -1, 10, -1, -1, 13 }; Node tree = creatTree(array, 0); System.out.println("武林網測試結果："); pre(tree); System.out.println(); pre1(tree); System.out.println(); mid(tree); System.out.println(); mid1(tree); System.out.println(); last(tree); System.out.println(); last1(tree); System.out.println(); ceng(tree); }}運行結果：
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希望本文所述對大家java程序設計有所幫助。