Решение

class Solution {
    fun maxProfit(prices: IntArray): Int {
        var mn = prices[0]
        var best = 0
        var i = 1
        val n = prices.size
        while (i < n) {
            val p = prices[i]
            if (p < mn) mn = p else {
                val d = p - mn
                if (d > best) best = d
            }
            i++
        }
        return best
    }
}