func findDisappearedNumbers(nums []int) []int {
    
    if len(nums) < 1{
        return []int{}
    }
    
    var missing []int
    
    for i := 1; i < len(nums)+1; i++{
        if !findInt(nums, i){
            missing = append(missing, i)
        }
    }
    
    return missing
}

func findInt(nums []int, num int) bool{
    
    for _,n := range nums{
        if n == num{
            return true
        }
    }
    return false
    
}