https://www.codingame.com/training/medium/telephone-numbers

codingame-phone-number.groovy

input = new Scanner(System.in);


N = input.nextInt()
numbers=[]
for (i = 0; i < N; ++i) {
    numbers << input.next()
}
int numberOfDigit(List<String> phoneNumbers) {
    masterNode = new Node('#')
    phoneNumbers.each {
        insertNumber(masterNode,it)
    }
    return masterNode.size()-1
}

def insertNumber(Node root,String number) {
    parentNode = root
    number.each { c ->
        Node nextNode = parentNode.nodes.find { it.value == c }
        if (nextNode == null) {
            nextNode = new Node(c)
            parentNode.nodes.add(nextNode)
        }
        parentNode = nextNode
    }
}

class Node {
    def value
    def nodes = []
    Node(def value) {
        this.value=value
    }
    int size() {
        return 1+ nodes.inject(0) { r, i -> r += i.size() }
    }
}

println numberOfDigit(numbers)