September 2017 Update

Task/Rep-string/Kotlin/rep-string.kotlin

@@ -0,0 +1,37 @@
+// version 1.0.6
+
+fun repString(s: String): MutableList<String> {
+    val reps = mutableListOf<String>()
+    if (s.length < 2) return reps
+    for (c in s) if (c != '0' && c != '1') throw IllegalArgumentException("Not a binary string")
+    for (len in 1..s.length / 2) {
+        val t = s.take(len)
+        val n = s.length / len
+        val r = s.length % len
+        val u = t.repeat(n) + t.take(r)
+        if (u == s) reps.add(t)
+    }
+    return reps
+}
+
+fun main(args: Array<String>) {
+    val strings = listOf(
+        "1001110011",
+        "1110111011",
+        "0010010010",
+        "1010101010",
+        "1111111111",
+        "0100101101",
+        "0100100",
+        "101",
+        "11",
+        "00",
+        "1"
+    )
+    println("The (longest) rep-strings are:\n")
+    for (s in strings) {
+        val reps = repString(s)
+        val size = reps.size
+        println("${s.padStart(10)} -> ${if (size > 0) reps[size - 1] else "Not a rep-string"}")
+    }
+}