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.

判断两个给定的树是否相同，不追求效率，简单编码可以使用深度优先，递归的方式

先判断两个树p和q是否为空，为空返回true，在不为空时，若p和q的左子树有一个为空或是右子树有一个为空，则一定返回false

然后，继续递归，对p和q的左子树和右子树分别进行isSame(p, q)运算

C语言代码：

/**
 * Definition for a binary tree node.
 * struct TreeNode {
 *     int val;
 *     struct TreeNode *left;
 *     struct TreeNode *right;
 * };
 */
bool isSameTree(struct TreeNode* p, struct TreeNode* q) {
    if(p == NULL && q == NULL)
    {
        return 1;
    }
    else if(p == NULL || q == NULL)
    {
        return 0;
    }
    if(p->val != q->val)
    {
        return 0;
    }
    return isSameTree(p->left, q->left) && isSameTree(p->right, q->right);
}