Merge sorted arrays

You are given two arrays sorted in non-decreasing order: $a$ ($n$ elements) and $b$ ($m$ elements). Merge them into one array sorted in non-decreasing order.

The first line contains $n$, the second line the array $a$. The third line contains $m$, the fourth line the array $b$. $1 \le n, m \le 10^5$, $|a_i|, |b_i| \le 10^9$; both arrays are sorted.

A single line with $n + m$ numbers — the merged array.

The arrays are already sorted — there is no need to sort again. Use two pointers ($i$ and $j$): on each step write the smaller of $a_i$ and $b_j$ and advance its pointer. When one array runs out, append the rest of the other.