Quickly find out if there are two elements in array A that are equal to the integer x

public class quicksearch {      public static int  Getmiddle (List<integer> list, int low, int high)  {           integer temp = list.get (High);                while  (Low < high)  {                  while   (Low < high && list.get (Low)  < temp)  {                       low++;                  }                  List.set (High, list.get (Low));                 while   (Low < high && list.get (high)  > temp)  {                       high--;                  }                  List.set (Low, list.get (high));                 if  (List.get (High)  == temp)  {                     break;                 }          &nbsP;  }             list.set (High, &NBSP;TEMP);        return low;                       }          //first position 3 points     public static void  quicksearch (List<integer> list, int low, int high)  {          if  (Low < high)  {              int target = getmiddle (List, low,  high);             if  (target<2 )  {                return ;            }             int middle = getmiddle (list, low, target-1);             int lwoMiddle = 0;             if  (middle>0)  {                 lwomiddle = getmiddle (List, low, &NBSP;MIDDLE-1);            }             int highMiddle = target-1;             if (Middle+1 != target) {                 highMiddle =  Getmiddle (List, middle+1, target-1);            }             int lowLow = low;             int lowHigh = target-1;             int highLow = target+1;             int highHigh = high;             numsearch (List,target,lwomiddle,highmiddle,lowlow,lowhigh,highlow,highhigh );        }     }           //find matching add-ons     public static void  Numsearch (List<integer> list,int target,int lwomiddle,int highmiddle,int lowlow ,  int lowhigh,inT highlow,int highhigh) {        integer targetnum  = list.get (target);        integer lwomiddlenum =  List.get (Lwomiddle);        integer highmiddlenum =  List.get (Highmiddle);        boolean flag = true;         while (flag) {             if  (Lwomiddlenum + highmiddlenum > targetnum)  {                 recursionsearch (list, Lwomiddle+1,lowhigh,highlow,highmiddle-1,target);                 recursionsearch (List,lowlow,lwomiddle-1,highmiddle+1,highhigh,target);     &Nbsp;           recursionsearch (list,lowLow,lwoMiddle-1 , highlow,highmiddle-1,target);             }else  if  (Lwomiddlenum + highmiddlenum < targetnum)  {                 recursionsearch (List,lwoMiddle+1, Lowhigh,highmiddle+1,highhigh,target);             } else{                 System.out.println (lwomiddlenum+ " + " +highmiddlenum+ " = " +targetnum);                 flag = false;             }         }   &nBSP;}          public static void recursionsearch (List <integer> list, int lowlow, int lowhigh,int highlow,int highhigh,int  target) {        int lwomiddle = -1;         int highMiddle = -1;         if  (Lowlow < lowhigh)  {             lwomiddle = getmiddle (List, lowlow, lowhigh);            }        if  ( Highlow < highhigh)  {              highmiddle = getmiddle (List, highlow, highhigh);         }        if  (lwomiddle == -1 | |  highMiddle == -1 )  {             return;        }         numsearch (List,target,lwomiddle,highmiddle, lowlow, lowhigh, highlow, highhigh);     }               Public static void quick (List<integer> list,int search)  {          list.add (search);         if   (List.size ()  > 0)  {               quicksearch (List, 0, list.size ()  - 1);          }     }&nbsP;    public static void main (String[] args)  {         List<Integer> list = new ArrayList<Integer> ();         list.add (+);         List.add (3);         list.add (;      )   list.add (1);         list.add (9);         list.add (7);         list.add (one);         list.add (+);         list.add (5);         list.add (6);         Quick (list, 10);     }}

Complexity: n+ (N/2) LG (N/2).

Quickly find out if there are two elements in array A that are equal to the integer x