C Program for Merge Sort Arrange a List of Integers in Ascending order

1			#include<stdio.h>
2			void Merge_Sort(int a[],int n);
3			void mpass(int a[],int low,int high);
4			void msort(int a[],int low,int mid,int high);
5			int main()
6			{
7			int a[10];
8			int i,j,temp,n,key;
9			printf("Enter the no.of elements : ");
10			scanf("%d",&n);
11			for(i=0;i<n;i++)
12			{
13			printf("Enter a[%d] element : ",i);
14			scanf("%d",&a[i]);
15			}
16			printf("Before Sorting array elements are : ");
17			for(i=0;i<n;i++)
18			{
19			printf("%d ",a[i]);
20			}
21			Merge_Sort(a,n);
22			printf("\nafter Sorting array elements are : ");
23			for(i=0;i<n;i++)
24			{
25			printf("%d ",a[i]);
26			}
27			}
28			void Merge_Sort(int a[],int n)
29			{
30			mpass(a,0,n-1);
31			}
32			void mpass(int a[],int low,int high)
33			{
34			int mid;
35			if(low<high)
36			{
			mid=(low+high)/2;
			mpass(a,low,mid);
			mpass(a,mid+1,high);
			msort(a,low,mid,high);
			}
			}
			void msort(int a[],int low,int mid,int high)
			{
			int n,i,j,k;
			int b[20];
			n=low;
			i=low;
			j=mid+1;
			while(i<=mid&&j<=high)
			{
			if(a[i]<=a[j])
			{
			b[n]=a[i];
			i++;
			}
			else
			{
			b[n]=a[j];
			j++;
			}
			n++;
			}
			if(i>mid)
			{
			for(k=j;k<=high;k++)
			{
			b[n]=a[k];
			n++;
			}
			}
			else
			{
			for(k=i;k<=mid;k++)
			{
			b[n]=a[k];
			n++;
			}
			}
			for(k=low;k<=high;k++)
			a[k]=b[k];
			}
			OUTPUT:
			Enter the no.of elements : 5
			Enter a[0] element : 8
			Enter a[1] element : 4
			Enter a[2] element : 6
			Enter a[3] element : 2
			Enter a[4] element : 3
			Before Sorting array elements are : 8 4 6 2 3
			after Sorting array elements are : 2 3 4 6 8