## Saturday, May 18, 2013

### Merge Sort Algorithm with C source Codes

Here, I've presented the merge sort algorithm as the straight merge sort. The basic idea is to break the file into n subfiles of size 1 and merge adjacent disjoint pairs of files and repeating the process until we've single file remaining of size n.
The C Source codes is as follows:

`// Merge sort implementation in C`
``````#include<stdio.h>

void getdata(int arr[],int n)
{
int i;
printf("\nEnter the data:");
for(i=0;i<n;i++)
{
scanf("%d",&arr[i]);
}
}

void display(int arr[],int n)
{
int i;
printf(" ");
for(i=0;i<n;i++)
{
printf("%d ",arr[i]);
}
getchar();
}

void sort(int arr[],int low,int mid,int high)
{
int i,j,k,l,b;
l=low;
i=low;
j=mid+1;
while((l<=mid)&&(j<=high))
{
if(arr[l]<=arr[j])
{
b[i]=arr[l];
l++;
}
else
{
b[i]=arr[j];
j++;
}
i++;
}
if(l>mid)
{
for(k=j;k<=high;k++)
{
b[i]=arr[k];
i++;
}
}
else
{
for(k=l;k<=mid;k++)
{
b[i]=arr[k];
i++;
}
}
for(k=low;k<=high;k++)
{
arr[k]=b[k];
}
}

void partition(int arr[],int low,int high)
{
int mid;
if(low<high)
{
mid=(low+high)/2;
partition(arr,low,mid);
partition(arr,mid+1,high);
sort(arr,low,mid,high);
}
}

void main()
{
int arr;
int n;
printf("Enter number of data:");
scanf("%d",&n);
getdata(arr,n);
partition(arr,0,n-1);
printf("\nThe Sorted array is :\n");
display(arr,n);
getchar();
}

``````