Merge branch 'zhravan:main' into main

Author: kawpii

internal/exercises/solutions/18_strings_runes/strings_runes.go

@@ -0,0 +1,21 @@
+package strings_runes
+
+import "unicode/utf8"
+
+// countRunes returns the number of runes (Unicode code points) in a string.
+// Runes represent Unicode characters, which may be multi-byte.
+// For example, "hello" has 5 runes, and "你好世界" has 4 runes (not 12 bytes).
+func countRunes(s string) int {
+	return utf8.RuneCountInString(s)
+}
+
+// reverseString reverses a string by rune, preserving multi-byte characters.
+// It converts the string to a slice of runes, reverses the slice, then converts back.
+// This ensures multi-byte Unicode characters like "你" are kept intact.
+func reverseString(s string) string {
+	runes := []rune(s)
+	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
+		runes[i], runes[j] = runes[j], runes[i]
+	}
+	return string(runes)
+}