Method checkAncestors

javascript/1993-operations-on-tree.js:92–99

* Helper method to check ancestors * Time O(n) | Space O(1) * @param {number} index * @return {boolean}

(index)

     * @return {boolean}
     */
    checkAncestors(index) {
        let node = this.parent[index];
        while (node !== -1) {
            if (this.treeHash[node]) return false;
            node = this.parent[node];
        }
        return true;
    }

    /**
     * Helper method to check descendants