1773. Count Items Matching a Rule

You are given an array items, where each items[i] = [typei, colori, namei] describes the type, color, and name of the ith item. You are also given a rule represented by two strings, ruleKey and ruleValue.

The ith item is said to match the rule if one of the following is true:

  • ruleKey == "type" and ruleValue == typei.
  • ruleKey == "color" and ruleValue == colori.
  • ruleKey == "name" and ruleValue == namei.

Return the number of items that match the given rule.

 

Example 1:

Input: items = [["phone","blue","pixel"],["computer","silver","lenovo"],["phone","gold","iphone"]], ruleKey = "color", ruleValue = "silver"
Output: 1
Explanation: There is only one item matching the given rule, which is ["computer","silver","lenovo"].

Example 2:

Input: items = [["phone","blue","pixel"],["computer","silver","phone"],["phone","gold","iphone"]], ruleKey = "type", ruleValue = "phone"
Output: 2
Explanation: There are only two items matching the given rule, which are ["phone","blue","pixel"] and ["phone","gold","iphone"]. Note that the item ["computer","silver","phone"] does not match.

 

Constraints:

  • 1 <= items.length <= 104
  • 1 <= typei.length, colori.length, namei.length, ruleValue.length <= 10
  • ruleKey is equal to either "type", "color", or "name".
  • All strings consist only of lowercase letters.

Rust Solution

struct Solution;

impl Solution {
    fn count_matches(items: Vec<Vec<String>>, rule_key: String, rule_value: String) -> i32 {
        let i = match rule_key.as_str() {
            "type" => 0,
            "color" => 1,
            "name" => 2,
            _ => panic!(),
        };
        items
            .into_iter()
            .filter(|item| item[i] == rule_value)
            .count() as i32
    }
}

#[test]
fn test() {
    let items = vec_vec_string![
        ["phone", "blue", "pixel"],
        ["computer", "silver", "lenovo"],
        ["phone", "gold", "iphone"]
    ];
    let rule_key = "color".to_string();
    let rule_value = "silver".to_string();
    let res = 1;
    assert_eq!(Solution::count_matches(items, rule_key, rule_value), res);
    let items = vec_vec_string![
        ["phone", "blue", "pixel"],
        ["computer", "silver", "phone"],
        ["phone", "gold", "iphone"]
    ];
    let rule_key = "type".to_string();
    let rule_value = "phone".to_string();
    let res = 2;
    assert_eq!(Solution::count_matches(items, rule_key, rule_value), res);
}

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