1787. Make the XOR of All Segments Equal to Zero
Hard41.0% acceptance6,876 / 16,767 submissions
Asked by 2 companies
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You are given an array nums and an integer k. The XOR of a segment [left, right] where left <= right is the XOR of all the elements with indices between left and right, inclusive: nums[left] XOR nums[left+1] XOR ... XOR nums[right].
Return the minimum number of elements to change in the array such that the XOR of all segments of size k is equal to zero.
Example 1:
Input: nums = [1,2,0,3,0], k = 1 Output: 3 Explanation: Modify the array from [1,2,0,3,0] to from [0,0,0,0,0].
Example 2:
Input: nums = [3,4,5,2,1,7,3,4,7], k = 3 Output: 3 Explanation: Modify the array from [3,4,5,2,1,7,3,4,7] to [3,4,7,3,4,7,3,4,7].
Example 3:
Input: nums = [1,2,4,1,2,5,1,2,6], k = 3 Output: 3 Explanation: Modify the array from [1,2,4,1,2,5,1,2,6] to [1,2,3,1,2,3,1,2,3].
Constraints:
1 <= k <= nums.length <= 20000 <= nums[i] < 210
Hints
Hint 1
Let's note that for the XOR of all segments with size K to be equal to zeros, nums[i] has to be equal to nums[i+k]
Hint 2
Basically, we need to make the first K elements have XOR = 0 and then modify them.