Find All Numbers Disappeared In Array

class Solution {
	public:
		vector<int> findDisappearedNumbers(vector<int>& nums) {
        
        vector<int> result;
        int len = nums.size();
        
        for(int i = 0; i < len; i ++) {
            
            int m = abs(nums[i]) - 1;
            
            nums[m] = nums[m] > 0? -nums[m]: nums[m];
            
            
        }
        
        for(int i = 0; i < len; i++) {
            
            if(nums[i] > 0) result.push_back(i+1); 
            
        }
        
        return result;
        
    }



};