LeetCode: Summary Ranges Solution

Approach

On each iteration, init start and end to be equal to the iterated element

Keep assigning end while next element is greater than the current by one unit

If start !== end then it's a sub range

Implementation

1var summaryRanges = function (nums) {
2  let start, end
3  let res = []
4
5  for (let i = 0; i < nums.length; i++) {
6    start = end = nums[i]
7
8    for (; nums[i + 1] === nums[i] + 1; i++) {
9      end = nums[i + 1]
10    }
11
12    res.push(start === end ? "" + start : start + "->" + end)
13  }
14
15  return res
16}