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421. Maximum XOR of Two Numbers in an Array
Find the maximum XOR value obtainable by choosing any two numbers from an array.
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Maximum XOR of Two Numbers in an Array
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Problem Statement
Problem
Given an integer array nums, choose two different elements and compute their bitwise XOR. Return the largest XOR value you can obtain.
The two chosen elements may appear anywhere in the array, but they must be distinct indices.
Goal
Maximize:
[
nums[i] \oplus nums[j]
]
for all i != j.
Notes
- XOR compares numbers bit by bit.
- The answer is the maximum value, not the pair itself.
Input Format
- A single integer array
nums. - Each element is a non-negative integer.
Output Format
- Return one integer: the maximum XOR of any pair of distinct elements in
nums.
Constraints
2 <= nums.length0 <= nums[i](use the usual 32-bit integer range in practice)- Must choose two different indices
Examples
Sample cases returned by the problem API.
Example 1
Input
nums = [3, 10, 5, 25, 2, 8]
Output
28
Explanation
The best pair is 5 ^ 25 = 28.
Example 2
Input
nums = [0, 2, 5, 7]
Output
7
Explanation
One optimal pair is 2 ^ 5 = 7.
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