package q448

func findDisappearedNumbers(nums []int) []int {
	n := len(nums)
	ret := make([]int, n)
	for i := range ret {
		ret[i] = i + 1
	}
	for _, num := range nums {
		ret[num-1] = -1
	}
	p := 0
	for i := range ret {
		if ret[i] != -1 {
			ret[p] = ret[i]
			p++
		}
	}
	return ret[:p]
}

var _ = findDisappearedNumbers