Added the C progam under the algorithms/C/linked-lists folder that can add an element at a given position in the linked list. The position the element is to be added is taken as an input from the user. Added on 2nd October,2022 - by RaisaGhosh - https://github.com/RaisaGhosh

algorithms/C/linked-lists/Add-Element-at-Nth-Position-SinglyLinkedList.c

@@ -0,0 +1,120 @@
+// This program will help us to add an element at any position in a singly linked list.
+// Also this program will help us to insert a node at the end of the list.
+
+#include<stdio.h>
+#include<stdlib.h>
+
+typedef struct stud
+{
+	int info;	//stores the data of the node
+	struct stud *link;	//stores the pointer to the next node
+}Node;
+
+Node *start=NULL; // start is a pointer variable of Node type and it stores the address of first node
+
+void add_node(int data) // to add the data at the end of the linked list
+{
+	Node *newptr=NULL,*ptr;
+	newptr=(Node*)malloc(sizeof(Node));//A new node will be created and the adrress is stored in newptr
+	newptr->info=data;
+	newptr->link=NULL;
+	if(start==NULL)// If true, it means there is no Linked list at all
+	{
+		start=newptr; // start and newptr both are pointing to the same node
+	}
+	else
+	{
+		ptr=start;// It means start and ptr both are pointing to the same node
+	
+	while(ptr->link!=NULL)
+	{
+		ptr=ptr->link;// the value/ address of ptr->link will be stored in ptr
+	}
+	ptr->link=newptr;// store the address of newptr to ptr->link.  
+	//That is link the new node with the linked list
+}
+}
+
+void add_anypos(int pos,int data) // to add a the data at a particular position(stored in pos) of the linked list
+{
+	int step=1;
+    Node *newptr=NULL;
+    newptr=(Node*)malloc(sizeof(Node));//A new node will be created and the adrress is stored in newptr
+	newptr->info=data;
+	Node *tptr=start;
+    
+    if(pos == 1){
+        newptr->link=start;
+        return;
+    }
+
+	while(step<pos-1) 
+	{	
+		tptr=tptr->link;
+        ++step;
+	}
+
+    newptr->link=tptr->link;	//newptr->link points to the rest of the linked list after the given position
+	tptr->link=newptr;			//newptr is now added to the required position
+}
+
+
+void display()// to display the linked list
+{
+	Node *ptr;
+	ptr=start;// It means start and ptr both are pointing to the same node
+
+    printf("\nThe linked list is : \n");
+
+	while(ptr)
+	{
+		printf("%d->",ptr->info);
+		ptr=ptr->link;
+	}
+	printf("NULL\n");
+}
+
+
+int main()
+{
+ int value,pos,count=0;
+ char choice,choice_pos;
+
+ while(1)// while loop will execute for infinite time if the choice=='y'. 
+ //If choice=='n' or choice=='N' it will stop
+{
+  	printf("\nDo you want to insert(y/n)?");
+  	scanf("%c",&choice);	//accepting user's choice if they want to add more data to the linked list or not
+
+  	if(choice == 'y'||choice == 'Y')
+	{
+
+  	printf("\nEnter the info:");
+    scanf("%d",&value);// the value to be added to the linked list
+
+    fflush(stdin);
+
+    printf("\nDo you want to insert the data at a particular position(y/n)?");
+  	scanf("%c",&choice_pos);	//accepting user's choice if they want to add the data to a particular position or not
+    fflush(stdin);
+
+    if(choice_pos == 'y'||choice_pos == 'Y'){
+        printf("\nEnter the position: ");
+  	    scanf("%d",&pos);	// the position at which the value is to be added
+        add_anypos(pos,value);
+    }
+    else    add_node(value);	
+
+  	fflush(stdin);
+
+	}
+
+	else    break;
+
+}
+
+display();// It will display the entire linked list
+
+return 0;
+
+}