LeetCode: Sort Colors Solution

Approach

Counting occurences of 0, 1, 2

Overwrite the original array with the occurences

Implementation

1var sortColors = function (nums) {
2  const colorCount = nums.reduce((arr, num) => {
3    arr[num]++
4    return arr
5  }, new Int8Array(3))
6
7  for (let i = (j = 0); i < nums.length; i++) {
8    while (colorCount[j] === 0) j++
9
10    nums[i] = j
11
12    colorCount[j]--
13  }
14}

References

Original problem

Similar problems

Sort List

Wiggle Sort

Wiggle Sort II