I simply scan the array from the end to the beginning, updating a value that is the max from i to N-1. I then update the max_difference value and return it.

```
public class Solution {
public int maxProfit(int[] prices) {
int max = 0;
int max_diff = 0;
for (int i = prices.length - 1; i >= 0; i--) {
if (prices[i] > max) {
max = prices[i];
}
int diff = Math.abs(max - prices[i]);
if (diff > max_diff) {
max_diff = diff;
}
}
return max_diff;
}
}
```