Formatted question description: https://leetcode.ca/all/945.html

# 945. Minimum Increment to Make Array Unique (Medium)

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:

1. 0 <= A.length <= 40000
2. 0 <= A[i] < 40000

Related Topics:
Array

## Solution 1.

// OJ: https://leetcode.com/problems/minimum-increment-to-make-array-unique/

// Time: O(N)
// Space: O(1)
class Solution {
public:
int minIncrementForUnique(vector<int>& A) {
sort(A.begin(), A.end());
int ans = 0;
for (int i = 1; i < A.size(); ++i) {
if (A[i] > A[i - 1]) continue;
ans += A[i - 1] + 1 - A[i];
A[i] = A[i - 1] + 1;
}
return ans;
}
};


Java

class Solution {
public int minIncrementForUnique(int[] A) {
if (A == null || A.length <= 1)
return 0;
int increments = 0;
Arrays.sort(A);
int curValue = A;
int length = A.length;
for (int i = 1; i < length; i++) {
curValue = Math.max(curValue + 1, A[i]);
increments += curValue - A[i];
}
return increments;
}
}