What is the complexity of this specialized sorting

Question

I would like to know the complexity (as in O (...)) of the following sorting algorithm:

• There are B barrels
• which contain a total of N elements, are distributed unevenly over the barrels.
• Elements in each barrel are already sorted.

Sorting combines all the elements from each trunk in one sorted list:

• using an array of size B to store the last sorted element of each trunk (starting at 0)
• check each barrel (at the last stored index) and find the smallest element
• copy the element in the final sorted array, increase the counter of the array
• add the last sorted element for the trunk that we selected from
• complete these steps N times

or in pseudo code:

for i from 0 to N
    smallest = MAX_ELEMENT
    foreach b in B
        if bIndex[b] < b.length && b[bIndex[b]] < smallest
            smallest_barrel = b
            smallest = b[bIndex[b]]
    result[i] = smallest
    bIndex[smallest_barrel] += 1

, O (n), , , , , B , , N , B-. , , ?

Answer 1

, . 2 . N-1 , | B |, | B | - B ( ). (N-1) * | B | O (NB).

Answer 2

, . . , , , B. , O (B) N