Pairs from list python and Kotlin (Java)

pairs_from_list.kt

/**
 * Generates all possible unique pairs of elements from the input list.
 * @param items Input list of elements
 * @return Pairs containing all possible combinations
 * @throws IllegalArgumentException if the input list is null
 */
fun <T> combs(items: List<T>): List<Pair<T, T>> {
    require(items.isNotEmpty()) { "Input list cannot be empty" }

    return items.flatMapIndexed { index, item ->
        items.drop(index + 1).map { item to it }
    }
}


//Sample usage
combs(listOf(1, 2, 3, 4, 5)).forEach { println(it) }

pairs_from_list.py

def _comb_pairs(h, t):
    for e in t: yield h, e
    if len(t) > 1: yield from _comb_pairs(t[0], t[1:])

def comb_pairs(l): yield from _comb_pairs(l[0], l[1:])


# Sample usage
for i in comb_pairs((1, 2, 3, 4, 5)): print(i)