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nth element in linked list
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nth element in linked list
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// C++ program to find n'th
// node in linked list
#include <assert.h>
#include <bits/stdc++.h>
using namespace std;
// Link list node
class Node {
public:
int data;
Node* next;
};
/* Given a reference (pointer to
pointer) to the head of a list
and an int, push a new node on
the front of the list. */
void push(Node** head_ref, int new_data)
{
// allocate node
Node* new_node = new Node();
// put in the data
new_node->data = new_data;
// link the old list
// off the new node
new_node->next = (*head_ref);
// move the head to point
// to the new node
(*head_ref) = new_node;
}
// Takes head pointer of
// the linked list and index
// as arguments and return
// data at index
int GetNth(Node* head, int index)
{
Node* current = head;
// the index of the
// node we're currently
// looking at
int count = 0;
while (current != NULL) {
if (count == index)
return (current->data);
count++;
current = current->next;
}
/* if we get to this line,
the caller was asking
for a non-existent element
so we assert fail */
assert(0);
}
// Driver Code
int main()
{
// Start with the
// empty list
Node* head = NULL;
// Use push() to construct
// below list
// 1->12->1->4->1
push(&head, 1);
push(&head, 4);
push(&head, 1);
push(&head, 12);
push(&head, 1);
// Check the count
// function
cout << "Element at index 3 is " << GetNth(head, 3);
return 0;
}