MaxAlgorithm.kt

package other

import java.lang.IllegalArgumentException

/**
 *
 * Algorithm for finding the maximum value from a list
 *
 */

class MaxAlgorithm {

    fun <T : Comparable<T>> compute(items: List<T>) : T {
        if (items.isEmpty()) {
            throw IllegalArgumentException("items list is empty!")
        }
        var max = items[0]
        for (i in 1 until items.size) {
            if (max < items[i]) {
                max = items[i]
            }
        }
        return max
    }

    /**
     * returns the maximum element from the list recursively
     */
    fun <T : Comparable<T>> computeRecursive(items: List<T>) : T {
        if (items.isEmpty()) {
            throw IllegalArgumentException("items list is empty!")
        }
        if (items.size == 1) {
            return items.first()
        }
        val first = items.first()
        val others = items.subList(1, items.size)

        val max = computeRecursive(others)

        return if (first > max) first else max
    }

}