diff --git a/data_structures/linked_list/ascendingpriorityqueue.c b/data_structures/linked_list/ascendingpriorityqueue.c
new file mode 100644
index 00000000..fdce503b
--- /dev/null
+++ b/data_structures/linked_list/ascendingpriorityqueue.c
@@ -0,0 +1,286 @@
+/* Ascending priority queue using Linked List - Program to implement Ascending priority queue using Linked List */
+
+/*A priority queue is a special type of queue in which each element is associated with a priority and is served according 
+to its priority. If elements with the same priority occur, they are served according to their order in the queue.
+
+Generally, the value of the element itself is considered for assigning the priority.
+
+For example: The element with the highest value is considered as the highest priority element. However, in other cases, 
+we can assume the element with the lowest value as the highest priority element. In other cases, 
+we can set priorities according to our needs.
+
+In a queue, the first-in-first-out rule is implemented whereas, in a priority queue, the values are removed on the basis of priority. 
+The element with the highest priority is removed first.
+
+insert() - Would insert an element in a queue 
+delete() -  Would delete the smallest element in the queue
+*/
+
+
+#include  <stdio.h>
+#include  <stdlib.h>  
+#define  NULL  ((void*)0)
+
+struct  node
+{
+  int  data ;
+  struct  node  *next ;
+} ;
+
+struct  node  *front , *rear ;
+
+/* This function initializes the queue to empty by making both front and rear as NULL */
+void createqueue()
+{
+  front=rear=NULL ;
+}
+
+int  empty()
+{
+  if(front==NULL)
+    return  1 ;
+  else
+    return  0 ;
+}
+
+void  insert(int  x)
+{
+  struct  node  *pnode ;
+
+  pnode=(struct node*)malloc(sizeof(struct node)) ;
+  if(pnode==NULL)
+  {
+    printf("Memory overflow. Unable to insert.\n") ;
+    exit(1) ;
+  }
+
+  pnode->data=x ;  
+  pnode->next=NULL;   /* New node is always last node */
+
+  if(empty())
+      front=rear=pnode ;
+  else
+  {
+      rear->next=pnode ;
+      rear=pnode ;
+  }
+}
+
+int  removes()
+{
+  int  min ;
+  struct  node  *follow , *follow1 , *p , *p1 ;
+
+  if(empty())
+  {
+    printf("\nQueue Underflow. Unable to remove.") ;
+    exit(1) ;
+  }
+
+  /* finding the node with minimum value in the APQ.*/
+  p=p1=front ;
+  follow=follow1=NULL ;
+  min=front->data ;
+  while(p!=NULL)
+  {
+    if(p->data<min)
+    {
+   min=p->data ;
+   follow1=follow ;
+   p1=p ;
+    }
+    follow=p ;
+    p=p->next ;
+  }
+
+  /* Deleting the node with min value */
+
+  if(p1==front)  /* deleting first node.*/
+  {
+    front=front->next ;
+    if(front==NULL)  /* Deleting the only one node */
+      rear=NULL ;
+  }
+  else if(p1==rear)  /* Deleting last node */
+  {
+      rear=follow1 ;
+      rear->next=NULL ;
+  }
+  else      /* deleting any other node.*/
+      follow1->next=p1->next ;
+
+
+  free(p1) ;
+  return  min ;  /* DONT FORGET LAST 2 STATEMENTS.*/
+}
+
+void  show()
+{
+  struct  node  *p ;
+
+  if(empty())
+    printf("Queue empty. No data to display \n") ;
+  else
+  {
+    printf("Queue from front to rear is as shown: \n") ;
+
+    p=front ;
+    while(p!=NULL)
+    {
+      printf("%d ",p->data) ;
+      p=p->next ;
+    }
+
+    printf("\n") ;
+  }
+}
+
+void  destroyqueue()
+{
+  front=rear=NULL ;
+}
+
+int  main()
+{
+  int  x , ch ;
+
+  createqueue() ;
+
+
+  do
+  {
+    printf("\n\n  Menu: \n") ;
+    printf("1:Insert \n") ;
+    printf("2:Remove \n") ;
+    printf("3:exit \n") ;
+    printf("Enter your choice: ") ;
+    scanf("%d",&ch) ;
+
+    switch(ch)
+    {
+      case 1:
+      printf("Enter element to be inserted: ") ;
+      scanf("%d",&x) ;
+      insert(x) ;
+      show() ;
+      break ;
+
+      case 2:
+      x=removes() ;
+      printf("Element removed is: %d\n",x) ;
+      show() ;
+      break ;
+
+      case 3:
+      break ;
+    }
+  }
+  while(ch!=3) ;
+
+  destroyqueue() ;
+
+  return 0;
+}
+
+/* Output of the Program*/
+
+/*
+  Menu:
+1:Insert
+2:Remove
+3:exit
+Enter your choice: 1
+Enter element to be inserted: 12
+Queue from front to rear is as shown:
+12
+
+
+  Menu:
+1:Insert
+2:Remove
+3:exit
+Enter your choice: 1
+Enter element to be inserted: 1
+Queue from front to rear is as shown:
+12 1
+
+
+  Menu:
+1:Insert
+2:Remove
+3:exit
+Enter your choice: 1
+Enter element to be inserted: 14
+Queue from front to rear is as shown:
+12 1 14
+
+
+  Menu:
+1:Insert
+2:Remove
+3:exit
+Enter your choice: 1
+Enter element to be inserted: 3
+Queue from front to rear is as shown:
+12 1 14 3
+
+
+  Menu:
+1:Insert
+2:Remove
+3:exit
+Enter your choice: 1
+Enter element to be inserted: 5
+Queue from front to rear is as shown:
+12 1 14 3 5
+
+
+  Menu:
+1:Insert
+2:Remove
+3:exit
+Enter your choice: 2
+Element removed is: 1
+Queue from front to rear is as shown:
+12 14 3 5
+
+
+  Menu:
+1:Insert
+2:Remove
+3:exit
+Enter your choice: 2
+Element removed is: 3
+Queue from front to rear is as shown:
+12 14 5
+
+
+  Menu:
+1:Insert
+2:Remove
+3:exit
+Enter your choice: 2
+Element removed is: 5
+Queue from front to rear is as shown:
+12 14
+
+
+  Menu:
+1:Insert
+2:Remove
+3:exit
+Enter your choice: 2
+Element removed is: 12
+Queue from front to rear is as shown:
+14
+
+
+  Menu:
+1:Insert
+2:Remove
+3:exit
+Enter your choice: 2
+Element removed is: 14
+Queue empty. No data to display
+
+*/
diff --git a/data_structures/linked_list/queue_linked_list.c b/data_structures/linked_list/queue_linked_list.c
new file mode 100644
index 00000000..d9076fdb
--- /dev/null
+++ b/data_structures/linked_list/queue_linked_list.c
@@ -0,0 +1,149 @@
+/* Queue using Linked List - Program to create a queue ADT using linked list. ADT should support the following operations
+1)  Createqueue
+2)  Insert into the queue
+3)  Delete from the queue
+4)  destroyqueue
+*/
+
+/* queue q declared globally */
+
+#include <stdio.h>
+#include <stdlib.h>
+#define NULL 0	
+
+struct  node
+{
+  int  data ;
+  struct  node  *next ;
+} ;
+
+struct  queue
+{
+ struct  node  *front , *rear ;
+} ;
+
+struct  queue  q ;
+
+/* This function initializes the queue to empty by making both front and rear as NULL */
+void createqueue()
+{
+  q.front=q.rear=NULL ;
+}
+
+int  empty()
+{
+  if(q.front==NULL)
+    return  1 ;
+  else
+    return  0 ;
+}
+
+void  insert(int  x)
+{
+  struct  node  *pnode ;
+
+  pnode=(struct node*)malloc(sizeof(struct node)) ;
+  if(pnode==NULL)
+  {
+    printf("Memory overflow. Unable to insert.\n") ;
+    exit(1) ;
+  }
+
+  pnode->data=x ;
+  pnode->next=NULL ;   /* New node is always last node */
+
+  if(empty())
+      q.front=q.rear=pnode ;
+  else
+  {
+      (q.rear)->next=pnode ;
+      q.rear=pnode ;
+  }
+}
+
+int  removes()
+{
+  int  x ;
+  struct  node  *p ;
+
+  if(empty())
+  {
+    printf("Queue Underflow. Unable to remove.\n") ;
+    exit(1) ;
+  }
+
+  p=q.front ;
+  x=(q.front)->data ;
+  q.front=(q.front)->next ;
+  if(q.front==NULL)       /* Queue contained only one node */
+       q.rear=NULL ;
+  free(p) ;
+  return  x ;
+}
+
+void  show()
+{
+  struct  node  *p ;
+
+  if(empty())
+    printf("Queue empty. No data to display \n") ;
+  else
+  {
+    printf("Queue from front to rear is as shown: \n") ;
+
+    p=q.front ;
+    while(p!=NULL)
+    {
+      printf("%d ",p->data) ;
+      p=p->next ;
+    }
+
+    printf("\n") ;
+  }
+}
+
+void  destroyqueue()
+{
+  q.front=q.rear=NULL ;
+}
+
+int main()
+{
+  int  x , ch ;
+
+  createqueue() ;
+
+  do
+  {
+    printf("\n\n  Menu: \n") ;
+    printf("1:Insert \n") ;
+    printf("2:Remove \n") ;
+    printf("3:exit \n") ;
+    printf("Enter your choice: ") ;
+    scanf("%d",&ch) ;
+
+    switch(ch)
+    {
+      case 1:
+      printf("Enter element to be inserted: ") ;
+      scanf("%d",&x) ;
+      insert(x) ;
+      show() ;
+      break ;
+
+      case 2:
+      x=removes() ;
+      printf("Element removed is: %d\n",x) ;
+      show() ;
+      break ;
+
+      case 3:
+      break ;
+    }
+  }
+  while(ch!=3) ;
+
+  destroyqueue() ;
+
+ return 0;
+}
diff --git a/sorting/merge_sort_nr.c b/sorting/merge_sort_nr.c
new file mode 100644
index 00000000..624b7411
--- /dev/null
+++ b/sorting/merge_sort_nr.c
@@ -0,0 +1,110 @@
+/* Program to demonstrate non recursive merge sort */
+
+/* Merge sort is an effective sorting algorithm which falls under divide and conquer paradigm and produces a stable sort.
+ Merge sort repeatedly breaks down a list into several sublists until each sublist consists of a single element and merging those 
+ sublists in a manner that results into a sorted list.
+
+Bottom-Up Merge Sort Implementation:
+The Bottom-Up merge sort approach uses iterative methodology. It starts with the “single-element” array, and combines two adjacent elements and 
+also sorting the two at the same time. 
+The combined-sorted arrays are again combined and sorted with each other until one single unit of sorted array is achieved. */
+
+#include  <stdio.h>
+
+void  mergesort(int  x[ ] , int  n) ; 
+void  show(int  x[ ] , int  n) ;
+
+
+
+void  mergesort(int  x[ ] , int  n)
+{
+  int  temp[50] , i , j , k , lb1 , lb2 , ub1 , ub2 , size ;
+
+  size=1 ;
+  while(size<n)
+  {
+    lb1=0 ;
+    k=0 ;
+
+    while(lb1+size<n)
+    {
+      lb2=lb1+size ;
+      ub1=lb2-1 ;
+      if(ub1+size<n)
+		ub2=ub1+size ;
+      else
+		ub2=n-1 ;
+
+      i=lb1 ;
+      j=lb2 ;
+
+      while(i<=ub1&&j<=ub2)
+		if(x[i]<x[j])
+	  		temp[k++]=x[i++] ;
+		else
+	  		temp[k++]=x[j++] ;
+
+      while(i<=ub1)
+		temp[k++]=x[i++] ;
+
+      while(j<=ub2)
+		temp[k++]=x[j++] ;
+
+      lb1=ub2+1 ;
+    }
+
+    for(i=0 ; i<=ub2 ; i++)
+      x[i]=temp[i] ;
+
+    size=size*2 ;
+
+    show(x,n) ;
+  }
+}
+
+// function to show each pass
+void  show(int  x[ ] , int  n)
+{
+  int  i ;
+  for(i=0 ; i<n ; i++)
+    printf("%d " , x[i]) ;
+  printf("\n\n") ;
+}
+
+
+int  main() //main function
+{
+ int  i , n , x[20] ;
+
+ printf("Enter the number of elements: ") ;
+ scanf("%d",&n) ;
+ printf("Enter the elements:\n") ;
+ for(i=0 ; i<n ; i++)
+    scanf("%d",&x[i]) ;
+
+ mergesort(x,n) ;
+
+ printf("Sorted array is as shown:\n") ;
+ for(i=0 ; i<n ; i++)
+    printf("%d " , x[i]) ;
+ return 0;
+}
+
+/* Output of the Program*/
+/*
+Enter the number of elements: 5
+Enter the elements:
+15
+14
+13
+12
+11
+14 15 12 13 11
+
+12 13 14 15 11
+
+11 12 13 14 15
+
+Sorted array is as shown:
+11 12 13 14 15
+*/