From 8ac3f2a609d2b7d3f508e84f4cd130da1e5f19c7 Mon Sep 17 00:00:00 2001
From: Shubham Sah <42349247+shubhamsah@users.noreply.github.com>
Date: Sat, 23 May 2020 21:28:16 +0530
Subject: [PATCH 01/10] Create AscendingPriorityQueue.c

---
 data_structures/linked_list/APQ.C | 169 ++++++++++++++++++++++++++++++
 1 file changed, 169 insertions(+)
 create mode 100644 data_structures/linked_list/APQ.C

diff --git a/data_structures/linked_list/APQ.C b/data_structures/linked_list/APQ.C
new file mode 100644
index 00000000..5e49481d
--- /dev/null
+++ b/data_structures/linked_list/APQ.C
@@ -0,0 +1,169 @@
+/* Ascending priority queue using Linked List - Program to implement Ascending priority queue using Linked List */
+
+#include  <stdio.h>
+#include  <stdlib.h>  
+#define  NULL  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") ;
+    getch();
+    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.") ;
+    getch() ;
+    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;
+}
+

From 1494474db6e6167a4fee3e5127a4525835971dad Mon Sep 17 00:00:00 2001
From: Shubham Sah <42349247+shubhamsah@users.noreply.github.com>
Date: Sat, 23 May 2020 21:28:35 +0530
Subject: [PATCH 02/10] Delete APQ.C

---
 data_structures/linked_list/APQ.C | 169 ------------------------------
 1 file changed, 169 deletions(-)
 delete mode 100644 data_structures/linked_list/APQ.C

diff --git a/data_structures/linked_list/APQ.C b/data_structures/linked_list/APQ.C
deleted file mode 100644
index 5e49481d..00000000
--- a/data_structures/linked_list/APQ.C
+++ /dev/null
@@ -1,169 +0,0 @@
-/* Ascending priority queue using Linked List - Program to implement Ascending priority queue using Linked List */
-
-#include  <stdio.h>
-#include  <stdlib.h>  
-#define  NULL  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") ;
-    getch();
-    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.") ;
-    getch() ;
-    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;
-}
-

From 9ed17fc3c9c3ac4f7572cb266671894c67b57a30 Mon Sep 17 00:00:00 2001
From: Shubham Sah <42349247+shubhamsah@users.noreply.github.com>
Date: Sat, 23 May 2020 21:29:54 +0530
Subject: [PATCH 03/10] Create Ascending Priority Queue

Code to implement Ascending Priority Queue
---
 .../linked_list/ascendingPriorityQueue.c      | 169 ++++++++++++++++++
 1 file changed, 169 insertions(+)
 create mode 100644 data_structures/linked_list/ascendingPriorityQueue.c

diff --git a/data_structures/linked_list/ascendingPriorityQueue.c b/data_structures/linked_list/ascendingPriorityQueue.c
new file mode 100644
index 00000000..5e49481d
--- /dev/null
+++ b/data_structures/linked_list/ascendingPriorityQueue.c
@@ -0,0 +1,169 @@
+/* Ascending priority queue using Linked List - Program to implement Ascending priority queue using Linked List */
+
+#include  <stdio.h>
+#include  <stdlib.h>  
+#define  NULL  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") ;
+    getch();
+    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.") ;
+    getch() ;
+    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;
+}
+

From 2357e8bd69076199d0af849479f4985086bf7545 Mon Sep 17 00:00:00 2001
From: Shubham Sah <42349247+shubhamsah@users.noreply.github.com>
Date: Sat, 23 May 2020 21:44:41 +0530
Subject: [PATCH 04/10] Create MergeNR.c

Program to demonstrate Merge sort algorithm without recursion
---
 sorting/MERGENR.C | 82 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 82 insertions(+)
 create mode 100644 sorting/MERGENR.C

diff --git a/sorting/MERGENR.C b/sorting/MERGENR.C
new file mode 100644
index 00000000..81152949
--- /dev/null
+++ b/sorting/MERGENR.C
@@ -0,0 +1,82 @@
+/* Program to demonstrate non recursive merge sort */
+
+#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;
+}

From 23df4b58d8e247a282b00d6e38973840c1a3ea40 Mon Sep 17 00:00:00 2001
From: Sombit Bose <sombit.bose15@gmail.com>
Date: Tue, 26 May 2020 20:58:51 +0530
Subject: [PATCH 05/10] Update File

A Demo Sample Test case added
---
 data_structures/linked_list/ascendingPriorityQueue.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/data_structures/linked_list/ascendingPriorityQueue.c b/data_structures/linked_list/ascendingPriorityQueue.c
index 5e49481d..0088262d 100644
--- a/data_structures/linked_list/ascendingPriorityQueue.c
+++ b/data_structures/linked_list/ascendingPriorityQueue.c
@@ -1,4 +1,15 @@
 /* Ascending priority queue using Linked List - Program to implement Ascending priority queue using Linked List */
+/** Input  State of Queue
+    1
+    2          2
+    1
+    3          2->3
+    2          3
+    3
+    
+    Output
+    2
+**/
 
 #include  <stdio.h>
 #include  <stdlib.h>  

From a652d51791fa0eeeb900bff776dec1bd5dc51d73 Mon Sep 17 00:00:00 2001
From: Shubham Sah <42349247+shubhamsah@users.noreply.github.com>
Date: Tue, 26 May 2020 21:06:32 +0530
Subject: [PATCH 06/10] Update AscendingPriorityQueue.c

Added the output of the file
---
 .../linked_list/ascendingPriorityQueue.c      | 113 ++++++++++++++++--
 1 file changed, 102 insertions(+), 11 deletions(-)

diff --git a/data_structures/linked_list/ascendingPriorityQueue.c b/data_structures/linked_list/ascendingPriorityQueue.c
index 0088262d..e55b7e8f 100644
--- a/data_structures/linked_list/ascendingPriorityQueue.c
+++ b/data_structures/linked_list/ascendingPriorityQueue.c
@@ -1,15 +1,4 @@
 /* Ascending priority queue using Linked List - Program to implement Ascending priority queue using Linked List */
-/** Input  State of Queue
-    1
-    2          2
-    1
-    3          2->3
-    2          3
-    3
-    
-    Output
-    2
-**/
 
 #include  <stdio.h>
 #include  <stdlib.h>  
@@ -178,3 +167,105 @@ int  main()
   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
+
+*/

From 2bdf7732d8e3a2e315f2a57d2493ea299239d0cb Mon Sep 17 00:00:00 2001
From: Shubham Sah <42349247+shubhamsah@users.noreply.github.com>
Date: Tue, 26 May 2020 21:11:22 +0530
Subject: [PATCH 07/10] Update MERGENR.C

Added output of the program
---
 sorting/MERGENR.C | 19 +++++++++++++++++++
 1 file changed, 19 insertions(+)

diff --git a/sorting/MERGENR.C b/sorting/MERGENR.C
index 81152949..3e32cad3 100644
--- a/sorting/MERGENR.C
+++ b/sorting/MERGENR.C
@@ -80,3 +80,22 @@ int  main() //main function
     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
+*/

From 2a4fd0b735711aeaafbeb5d6352ec9dbb9863d36 Mon Sep 17 00:00:00 2001
From: Shubham Sah <42349247+shubhamsah@users.noreply.github.com>
Date: Thu, 28 May 2020 11:29:24 +0530
Subject: [PATCH 08/10] Update and rename ascendingPriorityQueue.c to
 ascendingpriorityqueue.c

---
 ...iorityQueue.c => ascendingpriorityqueue.c} | 21 ++++++++++++++++---
 1 file changed, 18 insertions(+), 3 deletions(-)
 rename data_structures/linked_list/{ascendingPriorityQueue.c => ascendingpriorityqueue.c} (80%)

diff --git a/data_structures/linked_list/ascendingPriorityQueue.c b/data_structures/linked_list/ascendingpriorityqueue.c
similarity index 80%
rename from data_structures/linked_list/ascendingPriorityQueue.c
rename to data_structures/linked_list/ascendingpriorityqueue.c
index e55b7e8f..fdce503b 100644
--- a/data_structures/linked_list/ascendingPriorityQueue.c
+++ b/data_structures/linked_list/ascendingpriorityqueue.c
@@ -1,8 +1,25 @@
 /* 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  0
+#define  NULL  ((void*)0)
 
 struct  node
 {
@@ -34,7 +51,6 @@ void  insert(int  x)
   if(pnode==NULL)
   {
     printf("Memory overflow. Unable to insert.\n") ;
-    getch();
     exit(1) ;
   }
 
@@ -58,7 +74,6 @@ int  removes()
   if(empty())
   {
     printf("\nQueue Underflow. Unable to remove.") ;
-    getch() ;
     exit(1) ;
   }
 

From f4cbdd39cf846583ec179b2bea143e748a38486f Mon Sep 17 00:00:00 2001
From: Shubham Sah <42349247+shubhamsah@users.noreply.github.com>
Date: Thu, 28 May 2020 11:40:03 +0530
Subject: [PATCH 09/10] Update and rename MERGENR.C to merge_sort_nr.c

---
 sorting/{MERGENR.C => merge_sort_nr.c} | 9 +++++++++
 1 file changed, 9 insertions(+)
 rename sorting/{MERGENR.C => merge_sort_nr.c} (64%)

diff --git a/sorting/MERGENR.C b/sorting/merge_sort_nr.c
similarity index 64%
rename from sorting/MERGENR.C
rename to sorting/merge_sort_nr.c
index 3e32cad3..624b7411 100644
--- a/sorting/MERGENR.C
+++ b/sorting/merge_sort_nr.c
@@ -1,5 +1,14 @@
 /* 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) ; 

From b86a4747ca0bee5498b6035beb3ec1bcd74a5398 Mon Sep 17 00:00:00 2001
From: Shubham Sah <42349247+shubhamsah@users.noreply.github.com>
Date: Thu, 28 May 2020 12:26:56 +0530
Subject: [PATCH 10/10] Create queue_linked_list.c

Implementation of Queue using Linked List.
---
 .../linked_list/queue_linked_list.c           | 149 ++++++++++++++++++
 1 file changed, 149 insertions(+)
 create mode 100644 data_structures/linked_list/queue_linked_list.c

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;
+}