Create Maximum - Subproblems

Break the problem into three parts:

$1.$ Select i digits from nums1, k-i digits from nums2.: Try all valid splits.

$2.$ Get max number of length m from one array.: Use monotonic stack (similar to Remove K Digits).

$3.$ Merge two arrays into max number.: At each step, pick the lexicographically larger suffix. Combine: try all splits, merge each pair, keep the maximum result. The lexicographically larger suffix comparison in merging means: if $nums1[i:]$ > $nums2[j:]$ as arrays, pick from $nums1$. This tie-breaking rule ensures maximum result when both arrays have the same leading digit.