Solution using pseudocode and prove the time complexity and correctness!!!

Challenge Yourself. You are given an array A of non-negative integers. Every element except one has a duplicate. Design an algorithm that finds the element with no duplicate in O(n) time (You are promised that there is exactly one element with no duplicate). Example. A couple of examples for this problem: 1. A=[4,3,1,1,4] Output: 3 Explanation: 3 is the only number that does not have a duplicate 2. A=[3,1,4,5,1,4,3] Output: 5 Explanation: 5 is the only number that does not have a duplicate