XOR Queries of a Subarray
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Medium•bits•Expected: O(n + q) where n = arr length, q = number of queries time, O(n) for the prefix XOR array space
bit-manipulationprefix-sum
Problem
You are given an array arr of positive integers. You are also given the array queries where queries[i] = [lefti, righti].
For each query i compute the XOR of elements from lefti to righti (that is, arr[lefti] XOR arr[lefti + 1] XOR ... XOR arr[righti]).
Return an array answer where answer[i] is the answer to the ith query.
Constraints: 1 <= arr.length, queries.length <= 3 * 10^4. 1 <= arr[i] <= 10^9. 0 <= lefti <= righti < arr.length.
Example 1:
Input: arr = [1,3,4,8], queries = [[0,1],[1,2],[0,3],[3,3]]
Output: [2,7,14,8]
Explanation:
[0,1] = 1 xor 3 = 2
[1,2] = 3 xor 4 = 7
[0,3] = 1 xor 3 xor 4 xor 8 = 14
[3,3] = 8
Example 2:
Input: arr = [4,8,2,10], queries = [[2,3],[1,3],[0,0],[0,3]]
Output: [8,0,4,4]
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