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); } } }