#1664
Ways to Make a Fair Array
specialist · 610 · lc medium +29 · verified · 66.4% accepted · 1,397 likes · top 72%
Description
You are given an integer array nums. Choose exactly one index to remove. The remaining array is fair if the sum of elements at even indices equals the sum at odd indices (indices are renumbered after removal). Return the count of indices whose removal produces a fair array.
Example 1:
Input: nums = [2,1,6,4]
Output: 1
Explanation:
Remove index 0: [1,6,4] -> Even sum: 1 + 4 = 5. Odd sum: 6. Not fair.
Remove index 1: [2,6,4] -> Even sum: 2 + 4 = 6. Odd sum: 6. Fair.
Remove index 2: [2,1,4] -> Even sum: 2 + 4 = 6. Odd sum: 1. Not fair.
Remove index 3: [2,1,6] -> Even sum: 2 + 6 = 8. Odd sum: 1. Not fair.
There is 1 index that you can remove to make nums fair.
Example 2:
Input: nums = [1,1,1]
Output: 3
Explanation: You can remove any index and the remaining array is fair.
Example 3:
Input: nums = [1,2,3]
Output: 0
Explanation: You cannot make a fair array after removing any index.
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