Problem Statement

You are given two integers, lower and upper, specifying the inclusive range, and the sorted array of unique integers nums, where each element is in between [lower, upper].

We can say the number n is missing if n is not in the nums and falls in the range [lower, upper].

Return the shortest sorted list of ranges that covers all missing numbers. These ranges should fall within the inclusive bounds specified by the lower and upper limit integers.

Examples

Example 1:

• Input: nums = [0, 1, 3, 50, 75], lower = 0, upper = 99
• Expected Output: [[2, 2], [4, 49], [51, 74], [76, 99]]
• Justification: The missing ranges are 2, 4-49, 51-74, and 76-99. Each missing range is represented as a pair in the list, where both numbers are the same for a single missing number.

Example 2:

• Input: nums = [10, 20, 30, 40, 50], lower = 5, upper = 55
• Expected Output: [[5, 9], [11, 19], [21, 29], [31, 39], [41, 49], [51, 55]]
• Justification: The missing ranges are 5-9, 11-19, 21-29, 31-39, 41-49, and 51-55. Each interval is represented as a pair of start and end values.

Example 3:

• Input: nums = [1, 3, 6, 10], lower = 0, upper = 12
• Expected Output: [[0, 0], [2, 2], [4, 5], [7, 9], [11, 12]]
• Justification: The missing ranges are 0, 2, 4-5, 7-9, and 11-12. Each range is represented as a start and end pair.

Try it yourself

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