package arrays

func IndexOf[T comparable](a T, vs []T) int {
	for i, v := range vs {
		if v == a {
			return i
		}
	}
	return -1
}

func Exists[T comparable](a T, vs []T) bool {
	return IndexOf(a, vs) > -1
}

func Fill[T any](startIndex int, num uint, value T) map[int]T {
	m := make(map[int]T)
	var i uint
	for i = 0; i < num; i++ {
		m[startIndex] = value
		startIndex++
	}
	return m
}

func Reverse[T comparable](s []T) []T {
	for i, j := 0, len(s)-1; i < j; i, j = i+1, j-1 {
		s[i], s[j] = s[j], s[i]
	}
	return s
}

func Merge[T comparable](ss ...[]T) []T {
	n := 0
	for _, v := range ss {
		n += len(v)
	}
	s := make([]T, 0, n)
	for _, v := range ss {
		s = append(s, v...)
	}
	return s
}