see-448. Find All Numbers Disappeared in an Array

该题与442. Find All Duplicates in an Array题同理，殊途同归：

置位法和取负法分别如下:

class Solution {
public:
    vector<int> findDisappearedNumbers(vector<int>& nums) {
        vector<int> table;
        //table=place(nums,table);
        table=minus(nums,table);
        return table;
    }
    vector<int> place(vector<int> &nums,vector<int> &table) //置位法
    {
        int i=0;
        while(i<nums.size())
        {
            if(nums[i]!=i+1 && nums[i]!=nums[nums[i]-1]) 
            {
                int temp=nums[i]; // the relatting position
                nums[i]=nums[temp-1];
                nums[temp-1]=temp;
            }
            else
                i++;
        }
        
        for(int i=0;i<nums.size();i++)
        {
            if(i+1!=nums[i])
                table.push_back(i+1);
        }
        return table;
    }
     vector<int> minus(vector<int> &nums,vector<int> &table)  //取负法
     {
         for(int i=0;i<nums.size();i++)
         {
             int flag=abs(nums[i]);
             if(nums[flag-1]>0)
                 nums[flag-1]=-nums[flag-1];
         }
         
         for(int i=0;i<nums.size();i++)
         {
             if(nums[i]>0)
                 table.push_back(i+1);
         }
         return table;
     }
};