2089. Find Target Indices After Sorting Array

Description

You are given a 0-indexed integer array nums and a target element target.

A target index is an index i such that nums[i] == target.

Return a list of the target indices of nums after sorting nums in non-decreasing order. If there are no target indices, return an empty list. The returned list must be sorted in increasing order.

 

Example 1:

Input: nums = [1,2,5,2,3], target = 2
Output: [1,2]
Explanation: After sorting, nums is [1,2,2,3,5].
The indices where nums[i] == 2 are 1 and 2.

Example 2:

Input: nums = [1,2,5,2,3], target = 3
Output: [3]
Explanation: After sorting, nums is [1,2,2,3,5].
The index where nums[i] == 3 is 3.

Example 3:

Input: nums = [1,2,5,2,3], target = 5
Output: [4]
Explanation: After sorting, nums is [1,2,2,3,5].
The index where nums[i] == 5 is 4.

 

Constraints:

• 1 <= nums.length <= 100
• 1 <= nums[i], target <= 100

 

Solutions

Solution: Counting

• Time complexity: O(n)
• Space complexity: O(1)

 

JavaScript

/**
 * @param {number[]} nums
 * @param {number} target
 * @return {number[]}
 */
const targetIndices = function (nums, target) {
  const result = [];
  let start = 0;
  let count = 0;

  for (const num of nums) {
    if (num > target) continue;
    num === target ? (count += 1) : (start += 1);
  }

  for (let index = start; index < start + count; index++) {
    result.push(index);
  }

  return result;
};