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.

//简单比较两个树是否相同

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