Intuition

Straight forward string matching.

Follow-up: try the problem in a language known for it’s advanced type and value matching syntax such as Rust or OCaml.

Code

Python3

def countMatches(self, items: List[List[str]], ruleKey: str, ruleValue: str) -> int:
 
    ret = 0
 
    for t, c, n in items:
        if ruleKey == 'type':
            if t == ruleValue: ret += 1
        elif ruleKey == 'color':
            if c == ruleValue: ret += 1
        elif ruleKey == 'name':
            if n == ruleValue: ret += 1
    
    return ret

Big O Analysis

Runtime

The runtime complexity here is $O (N)$ since we are iterating over every item in the list.
Memory

The memory usage is $O (1)$ since we are not using any extra data structure.

— A

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