README.md

945. Minimum Increment to Make Array Unique

Given an array of integers nums, a move consists of choosing any nums[i], and incrementing it by 1.

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

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 with 5 or less moves that it is impossible for the array to have all unique values.

Note:

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

Solutions (Ruby)

1. Sort

# @param {Integer[]} nums
# @return {Integer}
def min_increment_for_unique(nums)
  nums.sort!
  ret = 0

  (1...nums.size).each do |i|
    ret += [nums[i], nums[i - 1] + 1].max - nums[i]
    nums[i] = [nums[i], nums[i - 1] + 1].max
  end

  ret
end

Solutions (Rust)

1. Sort

impl Solution {
    pub fn min_increment_for_unique(mut nums: Vec<i32>) -> i32 {
        nums.sort_unstable();
        let mut ret = 0;

        for i in 1..nums.len() {
            ret += nums[i].max(nums[i - 1] + 1) - nums[i];
            nums[i] = nums[i].max(nums[i - 1] + 1);
        }

        ret
    }
}