24 lines
448 B
Kotlin
24 lines
448 B
Kotlin
import java.util.Scanner
|
|
|
|
val scanner = Scanner(System.`in`)
|
|
|
|
val listLeft = ArrayList<Int>()
|
|
val listRight = ArrayList<Int>()
|
|
|
|
while (scanner.hasNextInt()) {
|
|
val num1 = scanner.nextInt()
|
|
listLeft.add(num1)
|
|
|
|
val num2 = scanner.nextInt()
|
|
listRight.add(num2)
|
|
}
|
|
|
|
|
|
val rightFrequencies = listRight.groupingBy { it }.eachCount()
|
|
|
|
val sum = listLeft.fold(0, { sum, left ->
|
|
sum + left * (rightFrequencies[left] ?: 0)
|
|
})
|
|
|
|
println(sum)
|
|
|