logo CodeStepByStep logo

split

Language/Type: C++ linked lists pointers
Author: Marty Stepp (on 2016/08/27)

Write a function named split that accepts a reference to a pointer to a ListNode representing the front of a linked list. Your function should rearrange the elements of the list so that all negative values appear before all of the non-negatives. The negatives should also appear in the opposite relative order that they appeared in the original list. For example, suppose a variable named front points to the front of a list containing the following sequence of values:

{8, 7, -4, 19, 0, 43, -8, -7, 2}

The call of split(front); should modify the list to contain the following elements, in exactly this order. Notice that the negatives were in the relative order -7, -8, -4 in the original list and are in the relative order -4, -8, -7 after the call.

{-7, -8, -4, 8, 7, 19, 0, 43, 2}

Constraints: Do not modify the data field of existing nodes; change the list by changing pointers only. Do not construct any new ListNode objects in solving this problem (though you may create as many ListNode* pointer variables as you like). Do not use any auxiliary data structures to solve this problem (no array, vector, stack, queue, string, etc).

Assume that you are using the ListNode structure as defined below:

struct ListNode {
    int data;         // value stored in each node
    ListNode* next;   // pointer to next node in list (NULL if none)
}
Type your solution here:


This is a function problem. Write a C++ function as described. Do not write a complete program; just the function(s) above.

You must log in before you can solve this problem.


Log In

If you do not understand how to solve a problem or why your solution doesn't work, please contact your TA or instructor.
If something seems wrong with the site (errors, slow performance, incorrect problems/tests, etc.), please

Is there a problem? Contact a site administrator.

© Marty Stepp, all rights reserved.