做题博客链接

https://blog.csdn.net/qq_43349112/article/details/108542248?spm=1001.2014.3001.5502

题目链接

https://leetcode-cn.com/problems/count-items-matching-a-rule/

描述

给你一个数组 items ，其中 items[i] = [typei, colori, namei] ，描述第 i 件物品的类型、颜色以及名称。

另给你一条由两个字符串 ruleKey 和 ruleValue 表示的检索规则。

如果第 i 件物品能满足下述条件之一，则认为该物品与给定的检索规则 匹配 ：

ruleKey == "type" 且 ruleValue == typei 。
ruleKey == "color" 且 ruleValue == colori 。
ruleKey == "name" 且 ruleValue == namei 。
统计并返回 匹配检索规则的物品数量 。

提示：

1 <= items.length <= 104
1 <= typei.length, colori.length, namei.length, ruleValue.length <= 10
ruleKey 等于 "type"、"color" 或 "name"
所有字符串仅由小写字母组成

示例

示例 1：

输入：items = [["phone","blue","pixel"],["computer","silver","lenovo"],
["phone","gold","iphone"]], ruleKey = "color", ruleValue = "silver"
输出：1
解释：只有一件物品匹配检索规则，这件物品是 ["computer","silver","lenovo"] 。

示例 2：

输入：items = [["phone","blue","pixel"],["computer","silver","phone"],["phone","gold","iphone"]],
 ruleKey = "type", ruleValue = "phone"
输出：2
解释：只有两件物品匹配检索规则，这两件物品分别是 ["phone","blue","pixel"] 和 
["phone","gold","iphone"] 。注意，["computer","silver","phone"] 未匹配检索规则。

初始代码模板

class Solution {
    
    
    public int countMatches(List<List<String>> items, String ruleKey, String ruleValue) {
    
    
       
    }
}

代码

class Solution {
    
    
    public int countMatches(List<List<String>> items, String ruleKey, String ruleValue) {
    
    
        //定义idx，表示要枚举的下标
        int idx = -1;
        if (ruleKey.equals("type")) {
    
    
            idx = 0;
        } else if (ruleKey.equals("color")) {
    
    
            idx = 1;
        } else {
    
    
            idx = 2;
        }

        int res = 0;
        for (List<String> list : items) {
    
    
            res += list.get(idx).equals(ruleValue) ? 1 : 0;
        }

        return res;
    }
}