{ "data": { "question": { "questionId": "1839", "questionFrontendId": "1720", "boundTopicId": null, "title": "Decode XORed Array", "titleSlug": "decode-xored-array", "content": "

There is a hidden integer array arr that consists of n non-negative integers.

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It was encoded into another integer array encoded of length n - 1, such that encoded[i] = arr[i] XOR arr[i + 1]. For example, if arr = [1,0,2,1], then encoded = [1,2,3].

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You are given the encoded array. You are also given an integer first, that is the first element of arr, i.e. arr[0].

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Return the original array arr. It can be proved that the answer exists and is unique.

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Example 1:

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\nInput: encoded = [1,2,3], first = 1\nOutput: [1,0,2,1]\nExplanation: If arr = [1,0,2,1], then first = 1 and encoded = [1 XOR 0, 0 XOR 2, 2 XOR 1] = [1,2,3]\n
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Example 2:

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\nInput: encoded = [6,2,7,3], first = 4\nOutput: [4,2,0,7,4]\n
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Constraints:

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Compiled with clang 11 using the latest C++ 20 standard.

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Your code is compiled with level two optimization (-O2). AddressSanitizer is also enabled to help detect out-of-bounds and use-after-free bugs.

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Most standard library headers are already included automatically for your convenience.

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OpenJDK 17. Java 8 features such as lambda expressions and stream API can be used.

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Python 2.7.12.

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C# 10 with .NET 6 runtime

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Node.js 16.13.2.

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Ruby 3.1

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Go 1.21

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Python 3.10.

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Rust 1.58.1

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PHP 8.1.

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With bcmath module

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