1773. Count Items Matching a Rule

Easy
​
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.

解題

Runtime: 30 ms, faster than 98.75%
Memory Usage: 6.9 MB, less than 72.50%
func countMatches(items [][]string, ruleKey string, ruleValue string) int {
ans := 0
​
if ruleKey == "type" {
for _, item := range items {
if item[0] == ruleValue { ans++ }
}
} else if ruleKey == "color" {
for _, item := range items {
if item[1] == ruleValue { ans++ }
}
} else {
for _, item := range items {
if item[2] == ruleValue { ans++ }
}
}
​
return ans
}