Java-8 solution

public static int minimumLoss(List prices) { int n = prices.size(); Map indexMap = new HashMap<>(); for (int i = 0; i < n; i++) { indexMap.put(prices.get(i), i); }

List<Long> sorted = new ArrayList<>(prices);
Collections.sort(sorted, Collections.reverseOrder());

long minLoss = Long.MAX_VALUE;
for (int i = 0; i < n - 1; i++) {
    long higher = sorted.get(i);
    long lower = sorted.get(i + 1);
    if (indexMap.get(higher) < indexMap.get(lower)) {
        minLoss = Math.min(minLoss, higher - lower);
    }
}

return (int) minLoss;

}