func zfillString(src string, z int) string {
	size := len(src)
	if size >= z {
		return src
	}

	fill := strings.Repeat("0", z-size)
	if strings.HasPrefix(src, "-") {
		return fmt.Sprintf("-%s%s", fill, src[1:])
	}
	return fmt.Sprintf("%s%s", fill, src)
}
func zfillString(src string, z int) string {
	size := len(src)
	if size >= z {
		return src
	}

	fill := strings.Repeat("0", z-size)
	if strings.HasPrefix(src, "-") {
		return fmt.Sprintf("-%s%s", fill, src[1:])
	}
	return fmt.Sprintf("%s%s", fill, src)
}
func zfillString ( src string , z int ) string { size := len ( src ) if size >= z { return src } fill := strings . Repeat ( " " , z - size ) if strings . HasPrefix ( src , " " ) { return fmt . Sprintf ( " " , fill , src [ 1 : ] ) } return fmt . Sprintf ( " " , fill , src ) }
// Left pads a string to a given with, using "0".
// If the string begins with a negative "-" character, then
// padding is inserted between the "-" and the remaining characters.
Left pads a string to a given with using 0 . If the string begins with a negative - character then padding is inserted between the - and the remaining characters .