CODEWITHSUNDEEP
javasortingsearchbinary
Arsalan Khan
Arsalan Khan

Reputation: 51

Binary search basic . Stuck in an Infinite loop

im trying to implement a basic form of binary search. i created an array and filled out with linear values. Now just trying to sort through it to find a number and its index.. The problem is that it is getting stuck in a constant loop and returning zero. it goes through the nested loop because it prints but is unable to find the target value. Below is the code 

for (int i= 1; i < 10000 ; i++){
        studentID[i] = i;
    }
   Students studentIDNumber = new Students();
   studentIDNumber.binarySearch(studentID, 400);


public void binarySearch(int[] studentID, int targetID){
    System.out.println("helloworld");
    int position = -1;
    int suspect;
    int suspectIndex = 0;
    int lastSuspectIndex = studentID.length-1;
    while(position == -1)
    {
        assert(suspectIndex<lastSuspectIndex);
        suspectIndex = ((studentID.length-1)/2);
        lastSuspectIndex =suspectIndex;
        suspect=studentID[suspectIndex];
        System.out.println(suspect);
        if(suspect == targetID){
            position = suspectIndex;
            System.out.println(suspectIndex +" is where the ID #"+targetID+" is sotred");
            break;
        }
         if(suspect < targetID){
            suspectIndex= suspectIndex+(suspectIndex/2); 
             position = -1;
            }
         if(suspect > targetID){
            suspectIndex= suspectIndex-(suspectIndex/2); 
            position = -1;}
        else {
            System.out.println("ID not found " );   
            }
    }

 }

Upvotes: 0

Views: 225

Answers (1)

dexsg
dexsg

Reputation: 56

On this line:

  suspectIndex = ((studentID.length-1)/2);

suspectIndex will be the same for every loop iteration. Initialize the variable once before the loop but not at the start of the loop itself.

Upvotes: 3

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