Searching.java

public class Searching {

      public static void main(String[] args) {
            int[] array = { 10, 25, 30, 15, 20 };
            int[] sarray = {10,20,30,55,65,87,98};//{ 15, 25, 35, 45, 55};
            int[] descarray = {98,58,48,32,22,20,10};
            int target = 22;
            
            int result = binarySearchReverse(descarray,target);//binarySearchR(sarray,target,0,sarray.length-1);//binarySearchI(sarray, target);
            if (result != -1) {
                System.out.println("Element found at index " + result);
            } else {
                System.out.println("Element not found in the array.");
            }
        }

    public static int linearSearchI(int[] arr, int target){
        for(int i=0 ; i<arr.length ; i++){
        // If the target is found at the current index, return the index
        if(arr[i]==target) return i;
        }
        // If the target is not found return -1
        return -1;
    }

    public static int linearSearchR(int[] arr, int target, int index) {
            // Base case: If the index is out of bounds, return -1 (element not found)
            if(index>=arr.length) return -1;
            // Base case: If the target is found at the current index, return the index
            if(arr[index]==target) return index;
            // Recursive case: Search the next element in the array
            return linearSearchR(arr, target, index+1);

        }
    
    public static int binarySearchI(int[] arr, int target) {
           int s=0,mid=0,e = arr.length-1;
           while(s<=e) {
            // Find Mid
               // mid = (s+e)/2;
               mid = s + (e-s)/2;
            // Element found at index mid
            if(arr[mid]==target) return mid;
            // Search in the right half
           else if(arr[mid]<target) s=mid+1;
            // Search in the left half
            else e = mid-1;
           }
            // Element not found in the array
            return -1;
    }

    public static int binarySearchReverse(int[] arr, int target) {
           int s=0,mid=0,e = arr.length-1;
           while(s<=e) {
            // Find Mid
               // mid = (s+e)/2;
               mid = s + (e-s)/2;
            // Element found at index mid
            if(arr[mid]==target) return mid;
            // Search in the right half
           else if(arr[mid]>target) s=mid+1;
            // Search in the left half
            else e = mid-1;
           }
            // Element not found in the array
            return -1;
    }

    
      public static int binarySearchR(int[] arr, int target, int start, int end) {
         if(start<=end)  {
         // Find Mid
            int mid = start+ (end-start)/2;
            // Element found at index mid
            if(arr[mid]==target) return mid;
            // Search in the right half
            else if(arr[mid]<target) return binarySearchR(arr,target,mid+1,end);
            // Search in the left half
            else  return binarySearchR(arr,target,start,mid-1);
        }
            // Element not found in the array
            return -1;
    }
    
    
}