checkPossibility.go

/* https://leetcode.com/problems/non-decreasing-array/description/
Given an array with n integers, your task is to check if it could become non-decreasing by modifying at most 1 element.

We define an array is non-decreasing if array[i] <= array[i + 1] holds for every i (1 <= i < n).

Example 1:
    Input: [4,2,3]
    Output: True
    Explanation: You could modify the first
    4
     to
    1
     to get a non-decreasing array.
Example 2:
    Input: [4,2,1]
    Output: False
    Explanation: You can't get a non-decreasing array by modify at most one element.
Note: The n belongs to [1, 10,000].
*/

package larray

func checkPossibility(nums []int) bool {
	for i, count := 0, 0; i < len(nums)-1; i++ {
		if nums[i] > nums[i+1] {
			count++
			if count > 1 {
				return false
			}
			if i > 0 && nums[i+1] < nums[i-1] {
				nums[i+1] = nums[i]
			} else {
				nums[i] = nums[i+1]
			}
		}
	}
	return true
}