1827. Minimum Operations to Make the Array Increasing

Problem

You are given an integer array nums (0-indexed). In one operation, you can choose an element of the array and increment it by 1.

• For example, if nums = [1,2,3], you can choose to increment nums[1] to make nums = [1,**3**,3].

Return **the *minimum* number of operations needed to make** nums *strictly increasing.*

An array nums is strictly increasing if nums[i] < nums[i+1] for all 0 <= i < nums.length - 1. An array of length 1 is trivially strictly increasing.

  Example 1:

Input: nums = [1,1,1]
Output: 3
Explanation: You can do the following operations:
1) Increment nums[2], so nums becomes [1,1,2].
2) Increment nums[1], so nums becomes [1,2,2].
3) Increment nums[2], so nums becomes [1,2,3].

Example 2:

Input: nums = [1,5,2,4,1]
Output: 14

Example 3:

Input: nums = [8]
Output: 0

  Constraints:

• 1 <= nums.length <= 5000

• 1 <= nums[i] <= 10^4

Solution (Java)

class Solution {
    public int minOperations(int[] nums) {
        int minsOps = 0;
        for (int i = 1; i < nums.length; i++) {
            if (nums[i] <= nums[i - 1]) {
                minsOps += nums[i - 1] - nums[i] + 1;
                nums[i] = nums[i - 1] + 1;
            }
        }
        return minsOps;
    }
}

Explain:

nope.

Complexity:

• Time complexity : O(n).
• Space complexity : O(n).