Challenge 2: filter, map, and reduce Chained — Solution

fun main() {
    val prices = listOf(12.50, 8.00, 25.00, 3.50, 40.00)

    val total = prices
        .filter { it > 10.0 }
        .map { it * 0.8 }
        .reduce { acc, price -> acc + price }

    println(total)
}

/*
Output:
62.0

Notes:
- filter { it > 10.0 } keeps 12.50, 25.00, and 40.00 (drops 8.00 and 3.50).
- map { it * 0.8 } applies a 20% discount to each remaining price:
  10.0, 20.0, 32.0.
- reduce { acc, price -> acc + price } sums those three discounted prices
  into a single total: 10.0 + 20.0 + 32.0 = 62.0.
- The three operators are chained directly, so the output of filter feeds
  into map, and the output of map feeds into reduce, with no intermediate
  variables needed.
*/