minor additions

Author: arorarahul

README.md

@@ -22,6 +22,11 @@ only if there is one number that repeats odd number of times
 which has to be returned
 - Sometimes if the algo seems to be complicated move to a generalized format where the result is assumed to be N and you are solving it for some x by going from solution to problem, and then try to figure out the algo. (refer question 28.c for more clarification)
 
+### For Linked Lists: (methods that can be applied)
+- Use multiple variables to not loose track of the linked list and keep moving them ahead in a manner such that various operations can be done on a linked list
+- If you dont want a function to return a value of something, just send that value to the address of the variable by passing the address of variable as argument and accessing it has **
+
+
 # General hash functions
 - take mod with number of elements present
 

linked-lists/question4.c

@@ -9,6 +9,22 @@ struct node{
 	struct node *link;
 };
 
+void reverse(struct node  **head){
+	//reversing the list
+	struct node *curr, *prev,*nextNode;
+	curr = *head;
+	
+	prev = NULL;
+	while(curr){
+		nextNode = curr->link;
+		curr->link = prev;
+		prev = curr;
+		curr = nextNode;
+		
+	}
+	*head = prev; //assigning the address the updated value
+}
+
 void printList(struct node *t){
 	if(t){
 		//interchanging these lines will print it in reverse order
@@ -41,20 +57,7 @@ int main(){
 	printList(t);
 	t = head;
 
-	//reversing the list
-	struct node *curr, *prev,*nextNode;
-	curr = head;
-	
-	prev = NULL;
-	while(curr){
-		nextNode = curr->link;
-		curr->link = prev;
-		prev = curr;
-		curr = nextNode;
-		
-	}
-	head = prev;
-
+	reverse(&head); //passing the address of the pointer pointing to the first address of the linked list
 	printList(head);
 
 }