Answer:If the restriction of not using additional memory is imposed, then the worst-case time complexity of finding an element in a sorted std::list would be O(n), where n is the number of elements in the list.
This is because a std::list is implemented as a linked list, and in order to find an element in a linked list, you must traverse the list from the beginning until you find the desired element. Since the list is sorted, you can stop traversing as soon as you reach an element that is greater than the one you are looking for, or if you reach the end of the list without finding the element.
However, since the list is not randomly accessible like an array, you cannot perform binary search, which would reduce the worst-case time complexity to O(log n), without using additional memory.
Step-by-step explanation: