题解 | #树的子结构#

还是人家的方法牛皮，记录一下，思路非常清晰。自己写的太乱啦！自己非递归，这篇递归。

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

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

    }

}
*/
import java.util.*;
public class Solution {
    public boolean HasSubtree(TreeNode root1,TreeNode root2) {
        if(root1 == null || root2 == null){
            return false;
        }
        return HasSubtree(root1.right,root2) || HasSubtree(root1.left,root2) || deep(root1,root2);
    }
    public boolean deep(TreeNode root1,TreeNode root2){
        if(root2 == null){
            return true;
        }
        if(root1 == null){
            return false;
        }
        if(root1.val != root2.val){
            return false;
        }
        return deep(root1.left,root2.left) && deep(root1.right,root2.right);
    }
}