#include <stdio.h>
int binarysearch(int a[], int low, int high, int x)
{
int mid = (low + high) / 2;
if (low > high)
return -1;
if (a[mid] == x)
return mid;
if (a[mid] < x)
return binarysearch(a, mid + 1, high, x);
else
return binarysearch(a, low, mid - 1, x);
}
int main(void)
{
int a[100];
int len, pos, search_item;
printf("Enter the length of the array\n");
scanf("%d", &len);
printf("Enter the array elements\n");
for (int i = 0; i < len; i++)
scanf("%d", &a[i]);
printf("Enter the element to search\n");
scanf("%d", &search_item);
pos = binarysearch(a, 0, len - 1, search_item);
if (pos < 0)
printf("Cannot find the element %d in the array.\n", search_item);
else
printf("The position of %d in the array is %d.\n", search_item, pos + 1);
return 0;
}
C Program for Merge Search using recursion function
#include <iostream>
using namespace std;
// A function to merge the two half into a sorted data.
void Merge(int *a, int low, int high, int mid)
{
// We have low to mid and mid+1 to high already sorted.
int i, j, k, temp[high - low + 1];
i = low;
k = 0;
j = mid + 1;
// Merge the two parts into temp[].
while (i <= mid && j <= high)
{
if (a[i] < a[j])
{
temp[k] = a[i];
k++;
i++;
}
else
{
temp[k] = a[j];
k++;
j++;
}
}
// Insert all the remaining values from i to mid into temp[].
while (i <= mid)
{
temp[k] = a[i];
k++;
i++;
}
// Insert all the remaining values from j to high into temp[].
while (j <= high)
{
temp[k] = a[j];
k++;
j++;
}
// Assign sorted data stored in temp[] to a[].
for (i = low; i <= high; i++)
{
a[i] = temp[i - low];
}
}
// A function to split array into two parts.
void MergeSort(int *a, int low, int high)
{
int mid;
if (low < high)
{
mid = (low + high) / 2;
// Split the data into two half.
MergeSort(a, low, mid);
MergeSort(a, mid + 1, high);
// Merge them to get sorted output.
Merge(a, low, high, mid);
}
}
int main()
{
int n, i;
cout << "\nEnter the number of data element to be sorted: ";
cin >> n;
int arr[n];
for (i = 0; i < n; i++)
{
cout << "Enter element " << i + 1 << ": ";
cin >> arr[i];
}
MergeSort(arr, 0, n - 1);
// Printing the sorted data.
cout << "\nSorted Data ";
for (i = 0; i < n; i++)
cout << "->" << arr[i];
return 0;
}
