Package g0201_0300.s0228_summary_ranges

Class Solution

  • public class Solution
extends Object
    228 - Summary Ranges.

    Easy

    You are given a sorted unique integer array nums.

    Return the smallest sorted list of ranges that cover all the numbers in the array exactly. That is, each element of nums is covered by exactly one of the ranges, and there is no integer x such that x is in one of the ranges but not in nums.

    Each range [a,b] in the list should be output as:

    • "a->b" if a != b
    • "a" if a == b

    Example 1:

    Input: nums = [0,1,2,4,5,7]

    Output: [“0->2”,“4->5”,“7”]

    Explanation: The ranges are: [0,2] –> “0->2” [4,5] –> “4->5” [7,7] –> “7”

    Example 2:

    Input: nums = [0,2,3,4,6,8,9]

    Output: [“0”,“2->4”,“6”,“8->9”]

    Explanation: The ranges are: [0,0] –> “0” [2,4] –> “2->4” [6,6] –> “6” [8,9] –> “8->9”

    Example 3:

    Input: nums = []

    Output: []

    Example 4:

    Input: nums = [-1]

    Output: [“-1”]

    Example 5:

    Input: nums = [0]

    Output: [“0”]

    Constraints:

    • 0 <= nums.length <= 20
    • -231 <= nums[i] <= 231 - 1
    • All the values of nums are unique.
    • nums is sorted in ascending order.

    • Constructor Detail

      • Solution

        public Solution()

    • Method Detail

      • summaryRanges

        public List<String> summaryRanges​(int[] nums)