#ifndef CA_UWATERLOO_ALUMNI_DWHARDER_SEARCHING_ALGORITHMS_INTERPOLATION_SEARCH_ARRAY
#define CA_UWATERLOO_ALUMNI_DWHARDER_SEARCHING_ALGORITHMS_INTERPOLATION_SEARCH_ARRAY

#include "Binary_search_array.h"

namespace Searching_algorithms {
	namespace Interpolation_search {
		int const ARRAY_USE_BINARY = 500;

		class Array {
			public:
				template <typename Type>
				static
				bool search( Type const &obj, Type *array, int n ) {
					if ( obj < array[0] || array[n - 1] < obj ) {
						return false;
					}

					return search_iterative( obj, static_cast<double>( obj ), array, 0, n - 1 );
				}

				template <typename Type>
				static
				bool search( Type const &obj, Type *array, int a, int b ) {
					if ( obj < array[a] || array[b] < obj ) {
						return false;
					}

					return search_iterative( obj, static_cast<double>( obj ), array, a, b );
				}

			private:
				template <typename Type>
				static
				bool search_iterative( Type const &obj, double d_obj, Type *array, int a, int c ) {
					while ( c - a >= ARRAY_USE_BINARY ) {
						if ( array[a] == array[c] ) {
							return array[a] == obj;
						}

						int b = a + static_cast<int>(
							static_cast<double>( c - a )*(d_obj - array[a])/static_cast<double>(array[c] - array[a])
						);

						if ( array[b] == obj ) {
							return true;
						} else if ( obj < array[b] ) {
							c = b - 1;

							if ( array[c] < obj ) {
								return false;
							}
						} else {
							a = b + 1;

							if ( array[a] > obj ) {
								return false;
							}
						}
					}

					return Searching_algorithms::Binary_search::Array::search( obj, array, a, c );
				}
		};
	}
}

#endif