1773. Count Items Matching a Rule

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

• class Solution {
public int countMatches(List<List<String>> items, String ruleKey, String ruleValue) {
int i = ruleKey.charAt(0) == 't' ? 0 : (ruleKey.charAt(0) == 'c' ? 1 : 2);
int ans = 0;
for (var v : items) {
if (v.get(i).equals(ruleValue)) {
++ans;
}
}
return ans;
}
}

• class Solution {
public:
int countMatches(vector<vector<string>>& items, string ruleKey, string ruleValue) {
int i = ruleKey[0] == 't' ? 0 : (ruleKey[0] == 'c' ? 1 : 2);
return count_if(items.begin(), items.end(), [&](auto& v) { return v[i] == ruleValue; });
}
};

• class Solution:
def countMatches(self, items: List[List[str]], ruleKey: str, ruleValue: str) -> int:
i = 0 if ruleKey[0] == 't' else (1 if ruleKey[0] == 'c' else 2)
return sum(v[i] == ruleValue for v in items)


• func countMatches(items [][]string, ruleKey string, ruleValue string) (ans int) {
i := map[byte]int{'t': 0, 'c': 1, 'n': 2}[ruleKey[0]]
for _, v := range items {
if v[i] == ruleValue {
ans++
}
}
return
}

• function countMatches(items: string[][], ruleKey: string, ruleValue: string): number {
const key = ruleKey === 'type' ? 0 : ruleKey === 'color' ? 1 : 2;
return items.reduce((r, v) => r + (v[key] === ruleValue ? 1 : 0), 0);
}


• impl Solution {
pub fn count_matches(items: Vec<Vec<String>>, rule_key: String, rule_value: String) -> i32 {
let key = if rule_key == "type" { 0 } else if rule_key == "color" { 1 } else { 2 };
items
.iter()
.filter(|v| v[key] == rule_value)
.count() as i32
}
}