题解 | #判断是不是平衡二叉树#

/*
 * function TreeNode(x) {
 *   this.val = x;
 *   this.left = null;
 *   this.right = null;
 * }
 */
/**
 * 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 bool布尔型
 */
function IsBalanced_Solution(pRoot) {
    if (!pRoot) return true;
    let diff = Math.abs(getHeight(pRoot.left) - getHeight(pRoot.right));
    return diff <= 1 && IsBalanced_Solution(pRoot.left) && IsBalanced_Solution(pRoot.right);
    // 编写函数求高度，使用后序遍历
    function getHeight(pRoot) {
        if (!pRoot) return 0;
        let leftHeight = getHeight(pRoot.left);
        let rightHeight = getHeight(pRoot.right);
        let height = Math.max(leftHeight, rightHeight) + 1;
        return height;
    }
}
module.exports = {
    IsBalanced_Solution: IsBalanced_Solution,
};