945. Minimum Increment to Make Array Unique

Problem Link

Description

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You are given an integer array nums. In one move, you can pick an index i where 0 <= i < nums.length and increment nums[i] by 1.

Return the minimum number of moves to make every value in nums unique.

The test cases are generated so that the answer fits in a 32-bit integer.

 

Example 1:

Input: nums = [1,2,2]
Output: 1
Explanation: After 1 move, the array could be [1, 2, 3].

Example 2:

Input: nums = [3,2,1,2,1,7]
Output: 6
Explanation: After 6 moves, the array could be [3, 4, 1, 2, 5, 7].
It can be shown that it is impossible for the array to have all unique values with 5 or less moves.

 

Constraints:

• 1 <= nums.length <= 105
• 0 <= nums[i] <= 105

Solution

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Python3

class Solution:
    def minIncrementForUnique(self, nums: List[int]) -> int:
        N = len(nums)
        res = 0
        curr = -1
        nums.sort()
 
        for x in nums:
            if x > curr:
                curr = x
            else: # curr >= x
                res += curr - x + 1
                curr += 1
 
        return res