Minimum Operations to Make Array Elements Unique

Problem Make all array elements unique using only increments (+1 per operation), minimizing the total number of increments.

Input / Output

• Input: int array nums. Output: minimum total increments.

Constraints

• n up to 10^5; O(n log n) expected.

Example

• [3,2,1,2,1,7] → 6 (e.g. [3,4,1,2,5,7]); [1,2,2] → 1.