LeetCode: Summary Ranges Solution

Approach

On each iteration, init

and to be equal to the iterated element

Keep assigning

while next element is greater than the current by one unit

If

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}