package com.interview.basics.search.array.sorted;
import com.interview.basics.search.array.ArraySearcher;
/**
* Created_By: stefanie
* Date: 14-11-2
* Time: 下午12:00
*/
public class RotatedArraySearcher<T extends Comparable<T>> extends ArraySearcher<T>{
protected RotatedArraySearcher(T[] input) {
super(input);
}
public T min(){
return min(0, input.length - 1);
}
private T min(int low, int high){
if(low == high) return input[low];
int mid = (low + high) / 2;
if(mid > low && input[mid - 1].compareTo(input[mid]) > 0) return input[mid];
if(input[mid].compareTo(input[high]) >= 0) return min(mid + 1, high);
else return min(low, mid - 1);
}
@Override
public T find(T element) {
return find(element, 0, input.length - 1);
}
private T find(T element, int low, int high){
if(low > high) return null;
int mid = (low + high)/2;
int cmp = element.compareTo(input[mid]);
if(cmp == 0) return input[mid];
else if(cmp < 0){
if(input[low].compareTo(input[mid]) <= 0 && element.compareTo(input[low]) < 0)
return find(element, mid + 1, high);
return find(element, low, mid - 1);
} else {
if(input[high].compareTo(input[mid]) >= 0 && element.compareTo(input[high]) > 0)
return find(element, low, mid - 1);
return find(element, mid + 1, high);
}
}
}