1365.js

// https://leetcode.com/problems/how-many-numbers-are-smaller-than-the-current-number/description/
//
// 1365. How Many Numbers Are Smaller Than the Current Number
//
// Given the array nums, for each nums[i] find out how many numbers in the array are smaller than it. That is, for each nums[i] you have to count the number of valid j's such that j != i and nums[j] < nums[i].
//
// Return the answer in an array.
//
//
//
// Example 1:
//
// Input: nums = [8,1,2,2,3]
// Output: [4,0,1,1,3]
// Explanation:
// For nums[0]=8 there exist four smaller numbers than it (1, 2, 2 and 3).
// For nums[1]=1 does not exist any smaller number than it.
// For nums[2]=2 there exist one smaller number than it (1).
// For nums[3]=2 there exist one smaller number than it (1).
// For nums[4]=3 there exist three smaller numbers than it (1, 2 and 2).
// Example 2:
//
// Input: nums = [6,5,4,8]
// Output: [2,1,0,3]
// Example 3:
//
// Input: nums = [7,7,7,7]
// Output: [0,0,0,0]
//
//
// Constraints:
//
// 2 <= nums.length <= 500
// 0 <= nums[i] <= 100
//
// /**
//  * @param {number[]} nums
//  * @return {number[]}
//  */
// var smallerNumbersThanCurrent = function(nums) {
//
// };

//Parameters: array of numbers
//Return: array of numbers
//Examples: Input: nums = [6,5,4,8] -> Output: [2,1,0,3]; Input: nums = [7,7,7,7] -> Output: [0,0,0,0]
//Pseudocode: create new sorted array. Loop through nums and get index of current element in sorted array.

/**
 * @param {number[]} nums
 * @return {number[]}
 */
var smallerNumbersThanCurrent = function (nums) {
  let sorted = [...nums].sort((a, b) => a - b);
  return nums.map((e) => sorted.indexOf(e));
};

//test
smallerNumbersThanCurrent([6, 5, 4, 8]); //[2,1,0,3]