import java.util.*;

public class Methods {
	
	final static Random die = new Random( 1954 );

	// simple testing of the select algorithm
	public static void main( String[] args ) {

		// determine whethers it uppercase or lowercase select		
		boolean lowercaseSelect;
		
		// determine what kth value means		
		int offset = 0;
		
		int[] ak = Methods.randomize( 200 );
		int[] ck = Methods.duplicate(ak);
		Arrays.sort(ck);
		
		int vk;
		int nk = ak.length;

		// if your select method is uppercase, change to Select.Select ***************
		vk = Select.select( ak, 0, nk-1, nk/4 );

		for (int i = -1; i <= 1; ++i) {
			if ( vk == ck[nk/4 + i] ) {
				offset = i;
				break;
			}
		}

		int[] cases = { 200, 1000, 5000, 10000, 50000 };
		int[] kValue = new int[5];

		for (int j = 0; j < cases.length; ++j ) {
			// create possible k values
			int n = cases[j];
			kValue[0] = 1;
			kValue[1] = n / 10;
			kValue[2] = n / 3;
			kValue[3] = n / 2;
			kValue[4] = 3 * n / 4;
			
			
			int [] a = Methods.randomize( n ); // test array
			int [] b = Methods.duplicate( a ); // dupicate of test array
			int [] c = Methods.duplicate( a );
			Arrays.sort( c );                  // sorted test array

			for (int i = 0; i < kValue.length; ++i ) {

				int k = kValue[i];
				int decrement = 0;
						
				int v;
					
				// if your select method is uppercase, change to Select.Select ***************
				v = Select.select( a, 0, a.length - 1, k );

				// is the answer correct
				if ( v != c[k + offset] ) {
					System.out.println("Failed test");
					System.out.println( "n: " + n + ", k: " + k + "  " + "got "
						+ v + " expected " + c[k + offset] );
					System.out.println("Array after manipulation");
					Methods.println( a ); System.out.println( "\n" ); // array after select manipulation
					System.out.println("Array before manipulation");
					Methods.println( b ); System.out.println( "\n" ); // array before select manipulation
					System.out.println("Array sorted");
					Methods.println( c ); System.out.println( "\n" ); // array sorted
					System.exit(k);
				}
			}

			// passed another set of tests
			System.out.println("Passed all tests for n = " + n);
		}

	}

	// returns an array of length m with elements randomly from 0 to n-1
	public static int[] randomize(int m, int n) {
		int[] a = new int[m];

		for (int i = 0; i < m; ++i) {
			a[i] = die.nextInt( n );
		}

		return a;
	}

	// returns an array of length m with elements randomly from 0 to largest positive integer
	public static int[] randomize(int m) {
		return randomize(m, Integer.MAX_VALUE );
	}

	// scrambles a
	public static void randomize(int[] a) {
		for (int i = a.length - 1; i > 0; --i) {
			int j = die.nextInt(i + 1);
			int rmbr = a[i];
			a[i] = a[j];
			a[j] = rmbr;
		}
	}

	// returns an array of length m where ith element equals i + n
	public static int[] identity(int m, int n) {
		int[] a = new int[m];

		for (int i = 0; i < m; ++i) {
			a[i] = i + n;
		}

		return a;
	}

	// returns an array of length m where ith element equals i
	public static int[] identity(int m) {
		return identity(m, 0);
	}

	// prints array elements with indices in the inclusive range left to right
	public static void print(int[] a, int left, int right) {
		for (int i = left; i <= right; ++i) {
			System.out.print( a[i] + " " );
		}
	}

	// prints all of the array elements
	public static void print(int[] a) {
		print( a, 0, a.length - 1);
	}

	// prints all of the array elements and does a newline
	public static void println(int[] a) {
		println(a, 0, a.length - 1);
	}

	// prints array elements with indices in the inclusive range left to right and then does a newline
	public static void println(int[] a, int left, int right) {
		print(a, left, right);
		System.out.println();
	}

	// returns a duplicate of array a
	public static int[] duplicate(int a[] ) {
		int[] b = new int[ a.length ];
		for (int i = 0; i < b.length; ++i) {
			b[i] = a[i];
		}
		
		return b;
	}

	// displays crucial debugging information from a select algorithm
	public static void debug(int[] a, int left, int right, int k) {
		System.out.println( "k: " + k + "  " + "left: " + left + " " + "right: " + right );
		println( a, left, right );
	}

	// returns whether the array is sorted
	public static boolean isSorted(int[] a) {
		for (int i = 1; i < a.length; ++i) {
			if ( a[i-1] > a[i] ) {
				return false;
			}
		}
		return true;
	}
}