go: add «2559. Count Vowel Strings in Ranges»

URL:	https://leetcode.com/problems/count-vowel-strings-in-ranges/
Signed-off-by: Matej Focko <me@mfocko.xyz>

go/count-vowel-strings-in-ranges.go

@@ -0,0 +1,38 @@
+package main
+
+import "slices"
+
+func vowelStrings(words []string, queries [][]int) []int {
+	isVowel := func(c byte) bool {
+		return slices.Contains([]byte{'a', 'e', 'i', 'o', 'u'}, c)
+	}
+
+	makePrefixCount := func() []int {
+		prefixCount := make([]int, len(words))
+
+		count := 0
+		for i, word := range words {
+			if isVowel(word[0]) && isVowel(word[len(word)-1]) {
+				count++
+			}
+			prefixCount[i] = count
+		}
+
+		return prefixCount
+	}
+	prefixCount := makePrefixCount()
+
+	answer := make([]int, len(queries))
+	for i, query := range queries {
+		till := prefixCount[query[1]]
+
+		preceding := 0
+		if query[0] != 0 {
+			preceding = prefixCount[query[0]-1]
+		}
+
+		answer[i] = till - preceding
+	}
+
+	return answer
+}