2 posts tagged with "divideAndConquer"

/**
 * Definition for a binary tree node.
 * function TreeNode(val, left, right) {
 *     this.val = (val===undefined ? 0 : val)
 *     this.left = (left===undefined ? null : left)
 *     this.right = (right===undefined ? null : right)
 * }
 */
/**
 * @param {number[]} nums
 * @return {TreeNode}
 */
var sortedArrayToBST = function (nums) {
  if (nums.length === 0) {
    return null;
  }
  return createBST(nums, 0, nums.length - 1);
};

const createBST = (nums, low, high) => {
  if (low > high) {
    return null;
  }

  let mid = Math.floor((high + low) / 2);

  let node = new TreeNode(nums[mid]);
  node.left = createBST(nums, low, mid - 1);
  node.right = createBST(nums, mid + 1, high);
  return node;
};

/**
 * @param {number[]} nums
 * @return {number}
 */
var majorityElement = function (nums) {
  const element = {};

  for (const num of nums) {
    if (element[num]) {
      element[num]++;
    } else {
      element[num] = 1;
    }
  }

  let max = 0;
  let targetNum = '';

  for (let e in element) {
    if (element[e] > max) {
      max = element[e];
      targetNum = e;
    }
  }

  return Number(targetNum);
};