main.go

package main

import "strings"

/*
In this Kata, you will be given a string that may have mixed uppercase and lowercase letters and your task is to convert
that string to either lowercase only or uppercase only based on:

make as few changes as possible.
if the string contains equal number of uppercase and lowercase letters, convert the string to lowercase.
For example:

solve("coDe") = "code". Lowercase characters > uppercase. Change only the "D" to lowercase.
solve("CODe") = "CODE". Uppercase characters > lowecase. Change only the "e" to uppercase.
solve("coDE") = "code". Upper == lowercase. Change all to lowercase.

More examples in test cases. Good luck!
*/

func isLower(char int32) bool {
	return 'a' <= char && char <= 'z'
}

func solve(str string) string {
	countLower := 0
	for _, char := range str {
		if isLower(char) {
			countLower++
		}
	}
	if countLower < len(str)-countLower {
		return strings.ToUpper(str)
	} else {
		return strings.ToLower(str)
	}
}