/*
	Bruce Maxwell
	Fall 2016
	CS 231 Project 1
	
	Flexible Array class for integers
 */

public class FlexArrayInt {

		int [] data; // the data
		int size;    // size of the array
		int ptr;     // next available space

		// constructor
		public FlexArrayInt() {
				data = new int[1]; // set up as default size 1
				size = 1;
				ptr = 0;
		}

		// adds an item to the end of the array
		public void add(int item) {
				int[] tmp;
				
				if(ptr >= size) { // need to allocate more data
						tmp = new int[size*2];

						// copy over the old data
						for(int i=0;i<size;i++) {
								tmp[i] = data[i];
						}

						// memory deallocation should occur here
						data = tmp;
						size = size * 2; // double the size
				}

				// make the assignment
				data[ptr] = item; 
				ptr++;
		}

		// accessor function
		public int get(int ix) {
				return data[ix];
		}

		// safe accessor function
		public int getSafe(int ix) {
				if(ix >= 0 && ix < ptr) {
						return data[ix];
				}

				System.out.println("getSafe: invalid index: " + ix );
				
				return 0;
		}

		// set function
		public void set(int ix, int val) {
				data[ix] = val;
		}

		// safe set function
		public void setSafe(int ix, int val) {
				if(ix >= 0 && ix < ptr) {
						data[ix] = val;
				}

				System.out.println("setSafe: invalid index: " + ix );
		}

		// utility function to return size of the data
		public int getSize() {
				return this.ptr;
		}

		// test function
		public static void main(String argv[] ) {
				FlexArrayInt f = new FlexArrayInt();

				System.out.println("Size: " + f.size + " Ptr: " + f.ptr);

				System.out.println("Adding 5");
				for(int i=0;i<5;i++) {
						f.add(i);
				}

				System.out.println("Size: " + f.size + " Ptr: " + f.ptr);
				for(int i=0;i<6;i++) {
						System.out.println( "Index: " + i + " Value: " + f.getSafe(i) );
				}


				System.out.println("Adding 5 more");
				for(int i=0;i<5;i++) {
						f.add(i);
				}
				System.out.println("Size: " + f.size + " Ptr: " + f.ptr);

		}
}