I really need a source code in C programming that uses merge sort in sorting an array. I need the most simplest and easiest program for me to understand it. Can you please help me?. thanks! godbless!!
Simple source code in C programming that implements "Merge Sort" in sorting an array.?
Example: 3 5 2 6 8
This is the function:
mergesort(int a[], int low, int high)
{
int mid;
if(low%26lt;high)
{
mid=(low+high)/2;
mergesort(a,low,mid);
mergesort(a,mid+1,high);
merge(a,low,high,mid);
}
return(0);
}
merge(int a[], int low, int high, int mid)
{
int i, j, k, c[50];
i=low;
j=mid+1;
k=low;
while((i%26lt;=mid)%26amp;%26amp;(j%26lt;=high))
{
if(a[i]%26lt;a[j])
{
c[k]=a[i];
k++;
i++;
}
else
{
c[k]=a[j];
k++;
j++;
}
}
while(i%26lt;=mid)
{
c[k]=a[i];
k++;
i++;
}
while(j%26lt;=high)
{
c[k]=a[j];
k++;
j++;
}
for(i=low;i%26lt;k;i++)
{
a[i]=c[i];
}
}
______________________________________...
______________________________________...
MergeSort uses divide %26amp; conquer strategy to sort the elements.
Here, you go on dividing till only one element is left.
Then this element will be merged with the next one and both will be put in correct order and since this is a recursive function, it will be repeated till you complete the merge and come out.
So, here is the sequence of calls:
a[] = {3, 5, 2, 6, 8}
low = 0; high = 4;
mergesort(a, 0, 4)
mid = 0 + 4 / 2 = 2
mergesort(a, 0, 2)
mergesort(a, 3, 4)
merge(a, 0, 4, 2)
So, each of the mergesort() calls will again go back and call mergesort() and merge(),
this goes on till: (low %26lt; high) is satisfied.
In the above example, there are only 5 elements; it is very easy to simulate. So, why don't you go on trying—as I showed—till it comes out. You will see a sorted list. It is worth doing this excercise, and in the end, you will know how it works.
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