Write a function named remove
that accepts a reference to a pointer to a ListNode
representing the front of a linked list, along with an index.
Your function should remove the node stored at the given index from the list.
For example, suppose a variable named front
points to the front of a list containing the following sequence of values:
{8, 23, 19, 7, 102}
The call of remove(front, 2);
should remove the value 19 from index 2, changing the list to store the following:
{8, 23, 7, 102}
The other values in the list should retain the same order as in the original list.
Your function should not leak memory; if your function removes a node, you should free (delete
) the memory used by the node.
If the list is already empty (null), your function should have no effect.
Otherwise, you may assume that the index passed is between 0 and the existing size of the list minus 1, inclusive.
Constraints:
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 modify the data
field of existing nodes; change the list by changing pointers only.
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 (nullptr if none)
}