Media of Sorted Arrays

#1

This code for some reason is giving wrong answer for all test cases after case 3, I tried getting the average of temp[n-1] and temp[n], but it isn’t working as well. Can you help me with this problem?

using namespace std;

void merge(vector &a, vector &b, vector &temp, int n)
{
int i = 0, j = 0, k = 0;

while (i < n && j < n)
{
    if (a[i] <= b[j])
        temp[k++] = a[i++];
    else
        temp[k++] = b[j++];
}

while (i < n)
    temp[k++] = a[i++];
while (j < n)
    temp[k++] = b[j++];

}

int main()
{
int n;
cin >> n;

vector<int> a(n), b(n), temp(n * 2);

for (int i = 0; i < n; i++)
    cin >> a[i];

for (int i = 0; i < n; i++)
    cin >> b[i];

merge(a, b, temp, n);

int med = n > 0 ? temp[n - 1]: -1;

cout << med << endl;

return 0;

}