1773. 统计匹配检索规则的物品数量Java

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# 题目

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。

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。

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

# 思路

用java stream流处理

# 解法

class Solution {
    public int countMatches(List<List<String>> items, String ruleKey, String ruleValue) {
        int ruleIndex = "type".equals(ruleKey) ? 0 : "color".equals(ruleKey) ? 1 : 2;
        return (int) items.stream()
                .filter(rule -> ruleValue.equals(rule.get(ruleIndex))).count();
    }
}

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# 总结

分析出几种情况，然后分别对各个情况实现

#Java