Find The Original Array of Prefix Xor | Leetcode 2433

 You are given an integer array pref of size n. Find and return the array arr of size n that satisfies:

• pref[i] = arr[0] ^ arr[1] ^ ... ^ arr[i].

Note that ^ denotes the bitwise-xor operation.

It can be proven that the answer is unique.

 

Example 1:

Input: pref = [5,2,0,3,1]
Output: [5,7,2,3,2]
Explanation: From the array [5,7,2,3,2] we have the following:
- pref[0] = 5.
- pref[1] = 5 ^ 7 = 2.
- pref[2] = 5 ^ 7 ^ 2 = 0.
- pref[3] = 5 ^ 7 ^ 2 ^ 3 = 3.
- pref[4] = 5 ^ 7 ^ 2 ^ 3 ^ 2 = 1.

Example 2:

Input: pref = [13]
Output: [13]
Explanation: We have pref[0] = arr[0] = 13.

 

Constraints:

• 1 <= pref.length <= 105
• 0 <= pref[i] <= 106

solution :

Hint :

if a xor b = c

then a xor c = b

and also b xor c = a

class Solution { public:     vector<int> findArray(vector<int>& pref) {                 int size = pref.size();           vector<int>arr;           for(int i =0 ; i < size ; i++)           {               if(i ==0)               {                   arr.push_back(pref[i]);               }               else               {                   arr.push_back(pref[i] ^ pref[i-1]);               }           }           return arr;     } };