LeetCode 945. Minimum Increment to Make Array Unique

原题链接在这里：https://leetcode.com/problems/minimum-increment-to-make-array-unique/

题目：

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

Constraints:

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

题解：

Sort the array.

For each number, it should be at least prev + 1.

If not, then accumlate prev + 1 - nums[i] to the result.

Time Complexity: O(nlogn). n = nums.length.

Space: O(1).

AC Java:

 1 class Solution {
 2     public int minIncrementForUnique(int[] nums) {
 3         if(nums == null || nums.length == 0){
 4             return 0;
 5         }
 6         
 7         Arrays.sort(nums);
 8         int res = 0;
 9         int prev = nums[0];
10         for(int i = 1; i < nums.length; i++){
11             int expect = prev + 1;
12             res += Math.max(expect - nums[i], 0);
13             prev = Math.max(expect, nums[i]);
14         }
15         
16         return res;
17     }
18 }

标签：unique,nums,int,res,Make,945,Minimum,array,prev
来源： https://www.cnblogs.com/Dylan-Java-NYC/p/16492673.html