What is causing the logic error in my code?

Question

I'm doing the "121. Best Time to Buy and Sell Stock" easy LeetCode problem but my output isn't correct and I can't figure out what I'm doing wrong. Here is the problem explanation:

You are given an array prices where prices[i] is the price of a given stock on the ith day.

You want to maximize your profit by choosing a single day to buy one stock and choosing a different day in the future to sell that stock.

Return the maximum profit you can achieve from this transaction. If you cannot achieve any profit, return 0.

Example 1:

Input: prices = [7,1,5,3,6,4]
Output: 5
Explanation: Buy on day 2 (price = 1) and sell on day 5 (price = 6), profit = 6-1 = 5.

Note that buying on day 2 and selling on day 1 is not allowed because you must buy before you sell.

Example 2:

Input: prices = [7,6,4,3,1]
Output: 0
Explanation: In this case, no transactions are done and the max profit = 0.

Here is what I've done so far:

class Solution {
    public int maxProfit(int[] prices) {
        
        int arrayLength = ((prices.length)*(prices.length + 1))/2;
        int[] profits = new int[arrayLength];
        int count = 0;

        for (int i = (prices.length - 1); i >= 0; i--)
        {
            for (int x = i; x >= 0; x--)
            {
                profits[count] = prices[i] - prices[x];
                count++;
            }
        }
        
        int maximumProfit = profits[0];
        for (int y = 1; y < profits.length; y++)
        {
            if (profits[y] > profits[y - 1])
                maximumProfit = profits[y];
        }

        return maximumProfit;
    }
}