Summary Ranges

Description

Given a sorted integer array without duplicates, return the summary of its ranges.

Example 1:

Input:  [0,1,2,4,5,7]
Output: ["0->2","4->5","7"]
Explanation: 0,1,2 form a continuous range; 4,5 form a continuous range.

Example 2:

Input:  [0,2,3,4,6,8,9]
Output: ["0","2->4","6","8->9"]
Explanation: 2,3,4 form a continuous range; 8,9 form a continuous range.

Solution(javascript)

/*
 * @lc app=leetcode id=228 lang=javascript
 *
 * [228] Summary Ranges
 */

// @lc code=start
/**
 * @param {number[]} nums
 * @return {string[]}
 */
const summaryRanges = function (nums) {
  let start = null
  const result = []
  for (let i = 0; i < nums.length; i++) {
    if (start === null) {
      start = nums[i]
    }
    if (nums[i] === nums[i + 1] - 1) {
      continue
    }
    if (nums[i] === start) {
      result.push(nums[i].toString())
      start = null
    } else {
      result.push(`${start}->${nums[i]}`)
      start = null
    }
  }
  return result
}
// @lc code=end