100. Same Tree

Posted 2020-08-08 Machelsky

思路：递归。

null也是tree。

null tree

(definition)

Definition: (1) A tree which is empty. (2) A tree whose leaf nodes all have a null value.

 https://xlinux.nist.gov/dads/html/nulltree.html

 

public class Solution {
    public boolean isSameTree(TreeNode p, TreeNode q) {
        if(p==null&&q==null)
        {
            return true;
        }
        if(p==null||q==null)
        {
            return false;
        }
        if(p.val==q.val)
        {
            return isSameTree(p.left,q.left)&&isSameTree(p.right,q.right);
        }
        else
        {
            return false;
        }
        
    }
}