[leetcode] 1720. Decode XORed Array

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

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].

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

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

 

  var decode = function(encoded, first) {
      let arr = [first];
      for(let i=1; i<=encoded.length; i++){
          arr.push(encoded[i-1]^arr[i-1]);
      }
      return arr;
  };