Решение

class Solution {
    fun longestCommonPrefix(strs: Array<String>): String {
        if (strs.isEmpty()) return ""
        var minLen = Int.MAX_VALUE
        for (s in strs) if (s.length < minLen) minLen = s.length
        if (minLen == 0) return ""
        var j = 0
        while (j < minLen) {
            val c = strs[0][j]
            var i = 1
            while (i < strs.size) {
                if (strs[i][j] != c) return strs[0].substring(0, j)
                i++
            }
            j++
        }
        return strs[0].substring(0, minLen)
    }
}