Status: IN
The two-pointer merge-scan pattern (maintain a pointer into each sorted sequence, advance the pointer on the smaller value, act on equality or exhaustion) is a recurring O(n+m) technique for processing paired elements from two sorted inputs — instantiated in merge-alternately (interleave by index), merge-nums (sum by matching ID), and min-common-number (return on first match).
Depth-1 cross-problem grouping: three solutions independently instantiate the same merge-scan template with different actions at the match/advance points
Depends on (SL): merge-alternately-linear-complexity, merge-nums-two-pointer-linear-time, two-pointer-merge-scan-for-sorted-intersection