38 lines
1.0 KiB
Kotlin
38 lines
1.0 KiB
Kotlin
// version 1.0.6
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fun extractRange(list: List<Int>): String {
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if (list.isEmpty()) return ""
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val sb = StringBuilder()
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var first = list[0]
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var prev = first
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fun append(index: Int) {
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if (first == prev) sb.append(prev)
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else if (first == prev - 1) sb.append(first, ",", prev)
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else sb.append(first, "-", prev)
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if (index < list.size - 1) sb.append(",")
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}
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for (i in 1 until list.size) {
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if (list[i] == prev + 1) prev++
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else {
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append(i)
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first = list[i]
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prev = first
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}
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}
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append(list.size - 1)
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return sb.toString()
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}
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fun main(args: Array<String>) {
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val list1 = listOf(-6, -3, -2, -1, 0, 1, 3, 4, 5, 7, 8, 9, 10, 11, 14, 15, 17, 18, 19, 20)
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println(extractRange(list1))
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println()
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val list2 = listOf(0, 1, 2, 4, 6, 7, 8, 11, 12, 14,
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15, 16, 17, 18, 19, 20, 21, 22, 23, 24,
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25, 27, 28, 29, 30, 31, 32, 33, 35, 36,
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37, 38, 39)
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println(extractRange(list2))
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}
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