题解 | #对称的二叉树#

/* function TreeNode(x) {
    this.val = x;
    this.left = null;
    this.right = null;
} */
function isSymmetrical(pRoot) {
    // write code here
    if (!pRoot) return true;
    function compare(node1, node2) {
        if (!node1 && !node2) return true;
        if (!node1 || !node2) return false;
        if (node1.val !== node2.val) {
            return false;
        } else {
            // 通过比较是否相等来判断，必须是两个条件同时满足才可
            return (
                compare(node1.left, node2.right) &&
                compare(node1.right, node2.left)
            );
        }
    }
    return compare(pRoot.left, pRoot.right);
}
module.exports = {
    isSymmetrical: isSymmetrical,
};