README_EN.md

1773. Count Items Matching a Rule

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Description

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.

Solutions

Python3

class Solution:
    def countMatches(self, items: List[List[str]], ruleKey: str, ruleValue: str) -> int:
        count = 0
        m = {
            'type': 0,
            'color': 1,
            'name': 2
        }
        return sum([item[m[ruleKey]] == ruleValue for item in items])

Java

class Solution {
    public int countMatches(List<List<String>> items, String ruleKey, String ruleValue) {
        int count = 0;
        for (List<String> item : items) {
            String t = item.get(0), c = item.get(1), n = item.get(2);
            if ("type".equals(ruleKey) && t.equals(ruleValue)) {
                ++count;
            } else if ("color".equals(ruleKey) && c.equals(ruleValue)) {
                ++count;
            } else if ("name".equals(ruleKey) && n.equals(ruleValue)) {
                ++count;
            }
        }
        return count;
    }
}

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