C/C++ Program for Median of two sorted arrays of same size?

Here we will see how to get the median of two sorted array of the same size. We will use C++ STL to store array elements. After getting two arrays, we will merge them into one. As two arrays of same size are merged, then the final array will always hold even number of elements. We need to take two middle elements, then get the average of them for the median.

Algorithm

median(arr1, arr2)

Begin
   arr3 := array after merging arr1 and arr2
   sort arr3
   len := length of arr3
   mid := len/2
   median := (arr3[mid] + arr3[mid-1])/2
   return median
End

Example

 Live Demo

#include<iostream>
#include<vector>
#include<algorithm>
using namespace std;
float median(vector<int> arr1, vector<int> arr2) {
   vector arr3(arr1.size() + arr2.size());
   merge(arr1.begin(), arr1.end(), arr2.begin(), arr2.end(), arr3.begin());
   sort(arr3.begin(), arr3.end());
   int len = arr3.size();
   int mid = len/2;
   return float(arr3[mid] + arr3[mid-1])/2;
}
main() {
   vector<int> arr1 = {1, 3, 4, 6, 7};
   vector<int> arr2 = {4, 5, 7, 8, 9};
   cout << "Median: " << median(arr1, arr2);
}

Output

Median: 5.5