题目：

题解：

func findDisappearedNumbers(nums []int) (ans []int) {
    n := len(nums)
    for _, v := range nums {
        v = (v - 1) % n
        nums[v] += n
    }
    for i, v := range nums {
        if v <= n {
            ans = append(ans, i+1)
        }
    }
    return
}