题解 | #二叉树的镜像#

/**
 * struct TreeNode {
 *	int val;
 *	struct TreeNode *left;
 *	struct TreeNode *right;
 * };
 */
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param pRoot TreeNode类 
 * @return TreeNode类
 */
struct TreeNode* Mirror(struct TreeNode* pRoot ) {
    // write code here
    if(pRoot == NULL) {   //终止条件
        return NULL;
    }

    struct TreeNode* str;
    str = pRoot->left;     //本层功能
    pRoot->left = pRoot->right;
    pRoot->right = str;

    Mirror(pRoot->left);   //递归调用
    Mirror(pRoot->right);

    return pRoot;
}