How is the removal of the first element from a dynamic array performed and what are the complexity implications?

Removing the first element from a dynamic array (for example, std::vector in C++) requires shifting all subsequent elements one position to the left to fill the freed space. This is because a dynamic array stores elements in a contiguous block of memory.

Due to the need to shift elements, the delete operation for the first element has a time complexity of O(n), where n is the number of elements in the array.

Example in C++:

#include <vector>
#include <iostream>

int main() {
    std::vector<int> v = {1, 2, 3, 4, 5};
    // Remove the first element
    v.erase(v.begin());

    for (int x : v) {
        std::cout << x << " ";
    }
    // Output: 2 3 4 5
}

If you need to frequently remove elements from the beginning, it is better to use other data structures, such as std::deque or linked lists, where removal from the beginning is faster.