100. Same Tree

Given two binary trees, write a function to check if they are equal or not.

Two binary trees are considered equal if they are structurally identical and the nodes have the same value.

思路:如果p.val=q.val 递归判断p.left,q.left和p.right,q.right，否则 就不是

代码如下(已通过leetcode)

public class Solution {
    public boolean isSameTree(TreeNode p, TreeNode q) {
        if(p==null && q==null) return true;
        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);
        }
    }
}