isNice.kt

package nicestring

fun String.isNice(): Boolean {
// It doesn't contain substrings bu, ba or be;
/*fun String.condition1(): Boolean = !(contains("bu") || contains("ba")        || contains("be"))*/
    val doesNotContain = setOf("bu", "ba", "be").none { this.contains(it) }


// It contains at least three vowels (vowels are a, e, i, o and u);
/*fun String.condition2():Boolean = filter { it in "aeiou" }.count() >= 3*/
    val hasThreeVowels = count { it in "aeiou" } >= 3


/*It contains a double letter (at least two similar letters following
one another), like b in "abba"*/
/*fun String.condition3():Boolean = zipWithNext() { a, b -> a == b }.filter { it }.count() >= 1*/
    val hasDouble = zipWithNext().any { it.first == it.second }

    /*return ((condition1() && condition2()) || (condition1() && condition3()) || (condition2() && condition3())) }*/
    return listOf(doesNotContain, hasThreeVowels, hasDouble).count { it } >= 2

}