 # Help in median of two sorted arrays of same size

// A Simple Merge based O(n)
// solution to find median of
// two sorted arrays
#include <bits/stdc++.h>
using namespace std;

/* This function returns
median of ar1[] and ar2[].
Assumptions in this function:
Both ar1[] and ar2[]
are sorted arrays
Both have n elements /
int getMedian(int ar1[],
int ar2[], int n)
{
int i = 0; /
Current index of
i/p array ar1[] /
int j = 0; /
Current index of
i/p array ar2[] */
int count;
int m1 = -1, m2 = -1;

``````/* Since there are 2n elements,
median will be average of elements
at index n-1 and n in the array
obtained after merging ar1 and ar2 */
for (count = 0; count <= n; count++)
{
/* Below is to handle case where
all elements of ar1[] are
smaller than smallest(or first)
element of ar2[]*/
if (i == n)
{
m1 = m2;
m2 = ar2;
break;
}

/*Below is to handle case where
all elements of ar2[] are
smaller than smallest(or first)
element of ar1[]*/
else if (j == n)
{
m1 = m2;
m2 = ar1;
break;
}
/* equals sign because if two
arrays have some common elements */
if (ar1[i] <= ar2[j])
{
/* Store the prev median */
m1 = m2;
m2 = ar1[i];
i++;
}
else
{
/* Store the prev median */
m1 = m2;
m2 = ar2[j];
j++;
}
}

return (m1 + m2)/2;
``````

}

// Driver Code
int main()
{
int ar1[] = {1, 12, 15, 26, 38};
int ar2[] = {2, 13, 17, 30, 45};

``````int n1 = sizeof(ar1) / sizeof(ar1);
int n2 = sizeof(ar2) / sizeof(ar2);
if (n1 == n2)
cout << "Median is "
<< getMedian(ar1, ar2, n1) ;
else
cout << "Doesn't work for arrays"
<< " of unequal size" ;
getchar();
return 0;
``````

}

in this code why they are calling getMedian() with arr1+n/2 when m1 < m2