448. Find all Numbers disappeared in an Array

Given an array of integers where 1≤a[i]≤ n (n = size of array), some elements appear twice and others Appear once.

Find all the elements of [1, N] inclusive The does not appear in this array.

Could do it without extra space and in O (n) runtime? Assume the returned list does not count as extra space.

Example:

input:[4,3,2,7,8,2,3,1]output:[5,6]

Given an array of integers, where 1≤a[i]≤n (n = array length), some elements appear two times, and others occur once.

Look for all elements in [1, n] that do not appear in the array.

Can i solve it without using extra space and in O (n) run time? You can assume that the return list does not count for extra space.

Idea: Traverse directly on the original array. If so, set the position that it should be in a negative value. The last traversal, which is the missing value

1      PublicList<integer> Finddisappearednumbers (int[] nums) {2list<integer> result =NewArraylist<>();3          for(inti=0;i<nums.length;i++)4         {5             intval = Math.Abs (Nums[i])-1;6             if(Nums[val] > 0) {7Nums[val] =-Nums[val];8             }9         }Ten          for(inti = 0; i < nums.length; i++) { One             if(Nums[i] > 0) { AResult.add (i+1); -             } -         } the         returnresult;  -}

448. Find all Numbers disappeared in an Array