Question

In C++ please.

3. splice() is a specialized method that inserts one list into 
   another in constant time but destroys the first list. Explain
   why this may be implemented for the list but not for any other
   sequential container. Give an example usage of splice()

Answer 1

3. splice() is a specialized method that inserts one list into 
   another in constant time but destroys the first list. Explain
   why this may be implemented for the list but not for any other
   sequential container. Give an example usage of splice()

Ans:-

The list::splice() may be a built-in function in C++ STL which is employed to transfer elements from one list to a different .
We can use splice() function in 3 ways:
1.Transfer all the weather of list x into another list at some position.
2.Transfer only the element pointed by i from list x into another list at some position.
3.Transfers the range [first, last] from list x into another list at some position.

The splice() function move the element of list from one list to another list. But also at the time it's remove from one list to another list. splice() is a specialized method that inserts one list into another in constant time but destroys the first list. Rather it's change or empty the first lilst.

It's implement only for list because it's use list's index values for use splice function or we can say that to pass the parameters to the splice() function.

Syntax:

list1Name.splice (iterator position, list2)
                or 
listName.splice (iterator position, list2, iterator i)
                or 
list1Name.splice (iterator position, list2, iterator first, iterator last)

Parameters:

• position – Specifies the position where the weather are to be transfered.
• list2 – It specifies an inventory object of an equivalent type which is to be transfered.
• i – It specifies an iterator to the position of a component in list2 which is to be transfered.
• first, last – Iterators specifying a variety of elements in list2 which is to be transferred in list1. The range includes all the weather between first and last, including the element pointed by first but not the one pointed by last.

 usage of splice():-

The use of splice() function to remove element from one list at constant time and add it to anther list.

Example:-

// list::splice() function 
#include <bits/stdc++.h> 
using namespace std; 
  
int main() 
{ 
    // init lists 
    list<int> list1 = { a, b, c }; 
    list<int> list2 = { d, e }; 
    list<int> list3 = { f, g, h }; 
  
    // transfer all the elements of list2 
    list1.splice(list1.begin(), list2); 
  
    // at the beginning of list1 
    cout << "list list1 after splice operation" << endl; 
    for (auto x : list1) 
        cout << x << " "; 
  
    // transfer all the elements of list1 
    list3.splice(list3.end(), list1); 
  
    // at the end of list3 
    cout << "\nlist list3 after splice operation" << endl; 
    for (auto x : list3) 
        cout << x << " "; 
    return 0; 
} 

Output:-

list list1 after splice operation
d e a b c
list list3 after splice operation
f g h d e a b c