Expression evaluation count
Given a string of digits 'num' and an integer target, count how many distinct expressions you can form by inserting the binary operators '+', '-', and '*' between digits (concatenating adjacent digits into multi-digit operands) so the expression evaluates to target. Operands may not have leading zeros (so '05' is disallowed, but a single '0' is fine). Standard precedence applies (multiplication binds tighter). 1 <= len(num) <= 10. Return the count.
Implement
count_target_expressions(num: str, target: int) → intExamples
in
["123",6]out2What a strong answer looks like
State 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.
0:00 of about 35 min
solution.py
InputExpectedGot
["123",6]2not run yetsample