剑指offer--4.13--树相关

输入两棵二叉树A，B，判断B是不是A的子结构。（ps：我们约定空树不是任意一个树的子结构）

/**
public class TreeNode {
int val = 0;
TreeNode left = null;
TreeNode right = null;

public TreeNode(int val) {
    this.val = val;

}

}
*/
public class Solution {
public boolean HasSubtree(TreeNode root1,TreeNode root2) {
    if(root1 == null || root2 == null)
        return false;
    return FS(root1.left,root2)||FS(root1.right,root2)||FS(root1,root2);
}

public boolean FS(TreeNode root1,TreeNode root2){
    if(root2 == null)
        return true;
    if(root1 == null)
        return false;
    if(root2.val != root1.val){
       return false;
    }
    return FS(root1.left,root2.left)&&FS(root1.right,root2.right);
}
}

操作给定的二叉树，将其变换为源二叉树的镜像。

/**
public class TreeNode {
int val = 0;
TreeNode left = null;
TreeNode right = null;
public TreeNode(int val) {
    this.val = val;
}
}

*/
public class Solution {
public void Mirror(TreeNode root) {
    if(root==null)
        return;
    TH(root);
    Mirror(root.left);
    Mirror(root.right);
}
public void TH(TreeNode root){
    TreeNode temp = root.left;
    root.left = root.right;
    root.right = temp;
}
}

输入一棵二叉树，求该树的深度。从根结点到叶结点依次经过的结点（含根、叶结点）形成树的一条路径，最长路径的长度为树的深度。

public class Solution {
public int TreeDepth(TreeNode root) {
    if(root==null){
        return 0;
    }
 	return  TreeDepth(root.left)> TreeDepth(root.right)?TreeDepth(root.left)+1:TreeDepth(root.right)+1;
}  
}