Walmart Global Tech Senior Software Engineer II interview questions

There was an assignment to be completed in 2 hours over a shared call with many candidates, asked to design a calendar app with certain operations. There were 2 rounds scheduled after a week from the assignment. Round 1st The question was to https://leetcode.com/problems/fair-candy-swap/ I could come up with the solution which of time complexity O(n) It took little time for me to arrive at the solution, he asked me to write the code, which I did code but he didn't bother to check my code at that time and simply asked me to finish it ASAP. This all took <40 mins. I was waiting for the 2nd round but no one joined then I got no feedback from HR. I submitted the same solution which I coded in above Leetcode link and all test cases were also passed. I think it was unfair to me as I was rejected even after providing the correct answer.