nth_node_from_end_in_linkedlist

nthnodefromend.cpp

@@ -0,0 +1,71 @@
+// C program to find n'th node from end using slow and 
+// fast pointers 
+#include<stdio.h> 
+#include<stdlib.h> 
+
+/* Link list node */
+struct Node 
+{ 
+int data; 
+struct Node* next; 
+}; 
+
+/* Function to get the nth node from the last of a linked list*/
+void printNthFromLast(struct Node *head, int n) 
+{ 
+struct Node *main_ptr = head; 
+struct Node *ref_ptr = head; 
+
+int count = 0; 
+if(head != NULL) 
+{ 
+	while( count < n ) 
+	{ 
+		if(ref_ptr == NULL) 
+		{ 
+		printf("%d is greater than the no. of "
+					"nodes in list", n); 
+		return; 
+		} 
+		ref_ptr = ref_ptr->next; 
+		count++; 
+	} /* End of while*/
+
+	while(ref_ptr != NULL) 
+	{ 
+		main_ptr = main_ptr->next; 
+		ref_ptr = ref_ptr->next; 
+	} 
+	printf("Node no. %d from last is %d ", 
+			n, main_ptr->data); 
+} 
+} 
+
+void push(struct Node** head_ref, int new_data) 
+{ 
+/* allocate node */
+struct Node* new_node = 
+		(struct Node*) malloc(sizeof(struct 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; 
+} 
+
+/* Drier program to test above function*/
+int main() 
+{ 
+/* Start with the empty list */
+struct Node* head = NULL; 
+push(&head, 20); 
+push(&head, 4); 
+push(&head, 15); 
+push(&head, 35); 
+
+printNthFromLast(head, 4); 
+}