- Difficulty: Medium
- Tags: LeetCode, Medium, Greedy, Array, Two Pointers, leetcode-2422, O(n), O(1), 🔒, Constructive Algorithms
Problem
You are given an array nums
consisting of positive integers.
You can perform the following operation on the array any number of times:
- Choose any two adjacent elements and replace them with their sum.
- For example, if
nums = [1,2,3,1]
, you can apply one operation to make it[1,5,1]
.
- For example, if
Return the minimum number of operations needed to turn the array into a palindrome.
Example 1:
Input: nums = [4,3,2,1,2,3,1] Output: 2 Explanation: We can turn the array into a palindrome in 2 operations as follows: - Apply the operation on the fourth and fifth element of the array, nums becomes equal to [4,3,2,3,3,1]. - Apply the operation on the fifth and sixth element of the array, nums becomes equal to [4,3,2,3,4]. The array [4,3,2,3,4] is a palindrome. It can be shown that 2 is the minimum number of operations needed.
Example 2:
Input: nums = [1,2,3,4] Output: 3 Explanation: We do the operation 3 times in any position, we obtain the array [10] at the end which is a palindrome.
Constraints:
1 <= nums.length <= 105
1 <= nums[i] <= 106