题解 | #将升序数组转化为平衡二叉搜索树#

/*
 * 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 nums int整型一维数组 
 * @return TreeNode类
 */
function sortedArrayToBST( nums ) {
    // write code here
     if (nums.length === 0) return null;

  function buildBST(left, right) {
    if (left > right) return null;

    const mid = Math.floor((left + right) / 2);
    const node = new TreeNode(nums[mid]);

    node.left = buildBST(left, mid - 1);
    node.right = buildBST(mid + 1, right);

    return node;
  }

  return buildBST(0, nums.length - 1);
}
module.exports = {
    sortedArrayToBST : sortedArrayToBST
};