Question
Implement substring search: return the index of the first occurrence of pat in text, or -1 if it does not occur. If pat is empty, return 0. Solve it in linear time using the Z-algorithm on the concatenation pat + sentinel + text (the sentinel must be a character that cannot appear in either input). For example, the first occurrence of "issip" in "mississippi" starts at index 4.
first_occurrence_z(text: str, pat: str) → int["mississippi","issip"]out4State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.
Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.