import java.util.List;// <T extends Comparable<T>>
public class SearchAlgorithms {

    public static boolean linearSearch(
        List<Integer> list,
        int value) {
           
        for (int data : list) {
            if (value == data) {
                return true;
            }
        }
        return false;
    }
 
    
    /* pre: list is sorted */
    public static boolean sortedLinearSearch(
        List<Integer> list,
        int value) {
        
        /* Attempts 1,2,3:
        int i = 0;
        while (list.get(i) < value && i < list.size() - 1) {
            i++;
        }
        return list.get(i) == value;
        */
        
        for (int data : list) {
            if (value == data) {
                return true;
            }
            if (value < data) {
                return false;
            }
        }
        return false;
    }
    
    
    public static <T extends Comparable<T>> boolean binarySearch(
        List<T> list, 
        T value) {
        return binarySearch(list, value, 0, list.size());
    }
    
    private static <T extends Comparable<T>> boolean binarySearch(
        List<T> list, 
        T value,
        int lo, int hi) {
        if (lo == hi) {
            return false;
        }
        if (lo == hi - 1) {
            return list.get(lo).compareTo(value) == 0;
        }
        
        int size = hi - lo;
        int mid = size/2 + lo;
        if (list.get(mid).compareTo(value) > 0) {
            //a.compareTo(b) > 0
            // a - b > 0
            // a > b
            return binarySearch(list, value, lo, mid);
        }
        else {
            return binarySearch(list, value, mid, hi);
        }
    }
}