// Supplementary to "Software Design ...", John A Robinson, Newnes, 2004,
//
//
// Java Program to implement ADT table of pairs
// using unordered array
//
//
import java.io.*;
import java.util.*;
// util is for StringTokenizer

class ipair {
	public int key;
	public int other_stuff;
	};

class table_of_pairs {
	int table_size;
	ipair ptable[];
	int num_in_table;
	public table_of_pairs(int size) 	{				
		num_in_table = 0; 
		table_size = size;
		// Set up an array of the requested size
		ptable = new ipair[table_size+1];
		// Now, being Java, we have to go through and construct the entries
		for (int i = 0; i < table_size+1; i++)
			ptable[i] = new ipair();
		};
	public int add_to_table(int key, int other) {
		remove_from_table(key);		// Remove any existing entry with this key value
		if (num_in_table == table_size)
			return(-1);		// table is full
		ptable[num_in_table].key = key;	// Add new item at the end of the list
		ptable[num_in_table++].other_stuff = other;
		return(0);
		}
	public int remove_from_table(int member) {
		int offset = 0;
		ptable[num_in_table].key = member;	// sentinel
		while (ptable[offset].key != member)
			offset++;// Keep going until find something with this key value
		if (offset == num_in_table)	// The one I found was the sentinel -
			return(-1);		// - so member is not in table
		// If member is in table, copy down final element in its place (to overwrite it)
		ptable[offset] = ptable[num_in_table - 1];
		num_in_table--;
		return(0);
		}
	public int get_other_stuff(int member, int other[]) {
		// Passing data back in other[0]
		int offset = 0;
		ptable[num_in_table].key = member;	// sentinel
		ptable[num_in_table].other_stuff = 0;	// set up, so that if key is not in table, this zero
							// value of other_stuff will get put into other 
		while(ptable[offset].key != member)
			offset++;
		other[0] = ptable[offset].other_stuff;
		if(offset != num_in_table)		// returns 0 if the one found was the sentinel
			return 1;
		return 0;
		}
	public int number_in() {
		return(num_in_table);
		};
	public void print_table() {
		int offset;
		for (offset = 0; offset < num_in_table; offset++)
			System.out.print(ptable[offset].key + "," + ptable[offset].other_stuff + " ");
		System.out.println();
		}
	};

//
// The main program here is just a simple test loop
// The commands q, a, r, c, p are available, to quit, add element,
// remove element, check for element, and print table repectively.
//
public class table_unorderedarray {
    public static void main(String args[]) throws java.io.IOException
	{
	char c;
	int key;
	int other[] = new int[1];
	// Other is a one element array to allow pass-by-reference
	table_of_pairs mytable = new table_of_pairs(8); 
	// Here saying that 8 is max num of elements I will use in 
	// any run of this test program (A bit restrictive).
	BufferedReader cin = new BufferedReader(new InputStreamReader(System.in));
	// Using BufferedReader to allow readLine into a String
	while(true)
		{
		System.out.print(": "); // Prompt
		String temp = cin.readLine();
		// Split input string into tokens
		StringTokenizer tokens = new StringTokenizer(temp);
		if (!tokens.hasMoreTokens())
			continue;
		temp = tokens.nextToken();
		switch(temp.charAt(0))
			{
			case 'q':
				return;
			case 'a':
				key = Integer.parseInt(tokens.nextToken());
				other[0] = Integer.parseInt(tokens.nextToken());
				mytable.add_to_table(key, other[0]);
				break;
			case 'r':
				key = Integer.parseInt(tokens.nextToken());
				mytable.remove_from_table(key);
				break;
			case 'c':
				key = Integer.parseInt(tokens.nextToken());
				if (mytable.get_other_stuff(key, other) != 0)
					System.out.println("Item labelled " +
	 key + " has value " + other[0] + " in mytable");
				else
					System.out.println("There is no item labelled " 
	+ key + " in mytable");
				break;
			case 'p':
				mytable.print_table();
				break;
			default:
				System.out.println("Use q, a, r, c or p only");
				break;
			}
		System.out.println(mytable.number_in() + " items in table");
		}
	}
    }