[CountTriplets] #practice

CountTriplets.groovy

class CountTriplets {
    static void main(String[] args) {
        // (-2, 0, 1) and (-2, 0, 3) == 2
        println "count=${count([-2, 0, 1, 3] as int[], 2)}"

        // (1, 3, 4), (1, 3, 5), (1, 3, 7), (1, 4, 5) == 4
        println "count=${count([5, 1, 3, 4, 7] as int[], 12)}"

        // (2, 3, 4), (2, 3, 5), (2, 3, 8), (2, 4, 5), (3, 4, 5) == 5
        println "count=${count([9, 5, 3, 2, 4, 8] as int[], 14)}"
    }

    static int count(int[] arr, int threshold) {
        if (arr.length < 3) return 0
        Arrays.sort(arr)
        int count = 0
        int i = 0, j = 1, k = 2

        while (i < arr.length) {
            if (k < arr.length) {
                int sum = arr[i] + arr[j] + arr[k]
                if (sum < threshold) {
                    println "(${arr[i]}, ${arr[j]}, ${arr[k]})"
                    count++
                }
                k++
            } else if (j < (arr.length - 1)) {
                j++
                k = j + 1
            } else {
                i++
                j = i + 1
                k = j + 1
            }
        }
        return count
    }
}