剑指offer-面试题19-二叉树的镜像

package case19_MirrorOfBinaryTree; public class MirrorOfBinaryTree { //完成二叉树的镜像操作 public static void MirrorTree(BinaryTreeNode root) { BinaryTreeNode tmpNode = null; if (root == null) { return; } if (root.lchild == null && root.rchild == null) return; tmpNode = root.lchild; root.lchild = root.rchild; root.rchild = tmpNode; MirrorTree(root.lchild); MirrorTree(root.rchild); } //*****TestCase start*****// //先序遍历二叉树 public static void printTree(BinaryTreeNode btn){ if(btn == null) return; System.out.print(btn.data + " "); printTree(btn.lchild); printTree(btn.rchild); } /** * 二叉树的镜像 * * @param args */ public static void main(String[] args) { // 8 // / \ // 6 10 // / \ / \ // 5 7 9 11 BinaryTreeNode root = new BinaryTreeNode(); root.data = 8; root.lchild = new BinaryTreeNode(); root.lchild.data = 6; root.lchild.lchild = new BinaryTreeNode(); root.lchild.lchild.data = 5; root.lchild.rchild = new BinaryTreeNode(); root.lchild.rchild.data = 7; root.rchild = new BinaryTreeNode(); root.rchild.data = 10; root.rchild.lchild = new BinaryTreeNode(); root.rchild.lchild.data = 9; root.rchild.rchild = new BinaryTreeNode(); root.rchild.rchild.data = 11; printTree(root); System.out.println(); MirrorTree(root); printTree(root); // 1 // / // 3 // / // 5 // / // 7 // / // 9 BinaryTreeNode root2 = new BinaryTreeNode(); root2.data = 1; root2.lchild = new BinaryTreeNode(); root2.lchild.data = 3; root2.lchild.lchild = new BinaryTreeNode(); root2.lchild.lchild.data = 5; root2.lchild.lchild.lchild = new BinaryTreeNode(); root2.lchild.lchild.lchild.data = 7; root2.lchild.lchild.lchild.lchild = new BinaryTreeNode(); root2.lchild.lchild.lchild.lchild.data = 9; System.out.println("\n"); printTree(root2); System.out.println(); MirrorTree(root2); printTree(root2); // 0 // \ // 2 // \ // 4 // \ // 6 // \ // 8 BinaryTreeNode root3 = new BinaryTreeNode(); root3.data = 0; root3.rchild = new BinaryTreeNode(); root3.rchild.data = 2; root3.rchild.rchild = new BinaryTreeNode(); root3.rchild.rchild.data = 4; root3.rchild.rchild.rchild = new BinaryTreeNode(); root3.rchild.rchild.rchild.data = 6; root3.rchild.rchild.rchild.rchild = new BinaryTreeNode(); root3.rchild.rchild.rchild.rchild.data = 8; System.out.println("\n"); printTree(root3); System.out.println(); MirrorTree(root3); printTree(root3); } //*****TestCase end*****// } package case19_MirrorOfBinaryTree; //构造二叉树节点 public class BinaryTreeNode { int data; BinaryTreeNode lchild; BinaryTreeNode rchild; public BinaryTreeNode(int data) { this.data = data; } public BinaryTreeNode(){ } }