Given an array of integers A, a move consists of choosing any A[i], and incrementing it by 1.
Return the least number of moves to make every value in A unique.
Example 1:
Input: [1,2,2]
Output: 1
Explanation:  After 1 move, the array could be [1, 2, 3].
Example 2:
Input: [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 with 5 or less moves that it is impossible for the array to have all unique values.
Note:
0 <= A.length <= 40000
0 <= A[i] < 40000
class Solution:
    def minIncrementForUnique(self, A):
        bar = -1
        res = 0
        for a in sorted(A):
            if a < bar:
                res += bar - a
            bar = max(bar + 1, a + 1)
        return res
class Solution:
    def minIncrementForUnique(self, A):
        bar = -1
        res = 0
        for a in sorted(A):
            if a < bar:
                res += bar - a
            bar = max(bar + 1, a + 1)
        return res