Lt1773. 统计匹配检索规则的物品数量

1773. 统计匹配检索规则的物品数量

给你一个数组 items ，其中 items[i] = [type, color, name] ，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 == type 。
• ruleKey == "color" 且 ruleValue == color 。
• ruleKey == "name" 且 ruleValue == name 。

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 <= 10
• 1 <= type.length, color.length, name.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

按照题意，根据 ruleKey 决定下标值，然后遍历数组判断值是否相等计数即可。

解答

/**
 * @param {string[][]} items
 * @param {string} ruleKey
 * @param {string} ruleValue
 * @return {number}
 */
var countMatches = function (items, ruleKey, ruleValue) {
  let index,
    res = 0;
  if (ruleKey === "type") index = 0;
  else if (ruleKey === "color") index = 1;
  else index = 2;
  for (const item of items) {
    if (item[index] === ruleValue) res++;
  }
  return res;
};