public class HW4Prob1 {

    public static boolean search(int [] arr, int x) {
        // check is x is there in sorted array arr
        return recSearch(arr, x, 0, arr.length-1);
    }

    private static boolean recSearch(int [] arr, int x, int left, int right) {
        // look for x in subarray arr[left,...,right]
        if (left > right) return false;
        int mid = (left + right)/2;
        if (x == arr[mid]) return true;
        if (x < arr[mid]) return recSearch(arr, x, , ); 
        return recSearch(arr, x, , );
        // fill in correctly the missing arguments in the recursive
        // calls of the two lines above.
    }

    public static void main(String [] args) {
	int [] A = {0,2,4,6,8,10,12,14,17,20};
        for(int i = 0; i < 10; i++) {
	    int x = (5*i) % 19; // some number to test
            System.out.println(search(A,x));
	}
    }
}