Create MergeNR.c

Program to demonstrate Merge sort algorithm without recursion

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;
+}