Merge k sorted lists

"""
"""
import heapq

def merge_k_sorted_lists(lists):
    min_heap = []
    for i, lst in enumerate(lists):
        if lst:
            heapq.heappush(min_heap, (lst[0], i, 0))

    merged_list = []
    while min_heap:
        val, list_idx, element_idx = heapq.heappop(min_heap)
        merged_list.append(val)
        if element_idx + 1 < len(lists[list_idx]):
            next_tuple = (lists[list_idx][element_idx + 1], list_idx, element_idx + 1)
            heapq.heappush(min_heap, next_tuple)

    return merged_list

# Example usage
lists = [[1, 4, 5], [1, 3, 4], [2, 6]]
print(merge_k_sorted_lists(lists))  # Output: [1, 1, 2, 3, 4, 4, 5, 6]