相同的树，递归，队列

package org.example.demo;  
  
import java.util.LinkedList;  
import java.util.Queue;  
  
//相同的树  
public class IsSameTreeSolution {  
public boolean isSameTree(TreeNode p,TreeNode q){  
    if(p==null&&q==null){  
        return true;  
    }else if(p==null||q==null){  
        return false;  
    }else if(p.val!=q.val){  
        return false;  
    }else{  
        return isSameTree(p.left,q.left)&&isSameTree(p.right,q.right);  
    }  
}  
public boolean isSameTreeTwo(TreeNode p,TreeNode q){  
    if(p==null && q==null){  
        return true;  
    }else if(p==null || q==null){  
        return false;  
    }  
    Queue<TreeNode> queue1=new LinkedList<TreeNode>();  
    Queue<TreeNode> queue2=new LinkedList<TreeNode>();  
    queue1.offer(p);  
    queue2.offer(q);  
    while (!queue1.isEmpty()&&!queue2.isEmpty()){  
        TreeNode node1=queue1.poll();  
        TreeNode node2=queue2.poll();  
        if(node1.val!=node2.val){  
            return false;  
        }  
        TreeNode left1=node1.left,right1=node1.right,  
        left2=node2.left,right2=node2.right;  
        if(left1==null^left2==null){  
            return false;  
        }  
        if(right1==null^right2==null){  
            return false;  
        }  
        if(left1!=null){  
            queue1.offer(left1);  
        }  
        if(right1!=null){  
            queue1.offer(right1);  
        }  
        if(left2!=null){  
            queue2.offer(left2);  
        }  
        if(right2!=null){  
            queue2.offer(right2);  
        }  
    }  
    return queue1.isEmpty()&&queue2.isEmpty();  
    }  
}  
class TreeNode{  
    TreeNode left,right;  
    int val;  
    TreeNode(){}  
    TreeNode(int val){this.val=val;}  
    TreeNode(TreeNode left,TreeNode right,int val){  
        this.left=left;  
        this.val=val;  
        this.right=right;  
    }  
}