inline fun <S, T : S> Sequence<T>.reduceIndexed(
    operation: (index: Int, acc: S, T) -> S
): S

Accumulates value starting with the first element and applying operation from left to right to current accumulator value and each element with its index in the original sequence.


operation -

function that takes the index of an element, current accumulator value and the element itself and calculates the next accumulator value.

The operation is terminal.